Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60128-2
Zhaoping Shi , Ziang Wang , Hongxiang Wu , Meiling Xiao , Changpeng Liu , Wei Xing
The development of high-performance oxygen evolution reaction catalysts with low iridium content is the key to the scale-up of proton exchange membrane water electrolyzer (PEMWE) for green hydrogen production. Single-site electrocatalysts with maximized atomic efficiency are held as promising candidates but still suffer from inadequate activity and stability in practical electrolyzer due to the low site density. Here, we proposed a NaNO3-assistant thermal decomposition strategy for the preparation of high-density Ir single sites on MnO2 substrate (NaNO3-H-Ir-MnO2). Direct spectroscopic evidence suggests the inclusion of NaNO3 accelerates the transformation of Ir-Cl to Ir-O coordination, thus generating uniform dispersed high-density Ir single sites in the products. The optimized H-Ir-MnO2 demonstrates not only high intrinsic activity in a three-electrode set-up but also boosted performance in scalable PEMWE, requiring a cell voltage of only 1.74 V to attain a high current density of 2 A cm‒2 at a low Ir loading of 0.18 mgIr cm‒2. This work offers a new insight for enhancing the industrial practicality of Ir-based single site catalysts.
开发铱含量低的高性能氧进化反应催化剂是扩大质子交换膜水电解槽（PEMWE）规模以实现绿色制氢的关键。原子效率最大化的单位点电催化剂被认为是有前途的候选催化剂，但由于位点密度低，在实际电解槽中仍存在活性和稳定性不足的问题。在此，我们提出了一种在 MnO2 基质上制备高密度 Ir 单位点（NaNO3-H-Ir-MnO2）的 NaNO3 辅助热分解策略。直接光谱证据表明，NaNO3 的加入加速了 Ir-Cl 配位向 Ir-O 配位的转变，从而在产物中生成了均匀分散的高密度 Ir 单位点。优化后的 H-Ir-MnO2 不仅在三电极设置中表现出很高的本征活性，而且在可扩展的 PEMWE 中的性能也得到了提升，在 0.18 mgIr cm-2 的低 Ir 负载条件下，只需 1.74 V 的电池电压就能达到 2 A cm-2 的高电流密度。这项工作为提高铱基单位点催化剂的工业实用性提供了新的视角。
{"title":"High-density Ir single sites from rapid ligand transformation for efficient water electrolysis","authors":"Zhaoping Shi , Ziang Wang , Hongxiang Wu , Meiling Xiao , Changpeng Liu , Wei Xing","doi":"10.1016/S1872-2067(24)60128-2","DOIUrl":"10.1016/S1872-2067(24)60128-2","url":null,"abstract":"<div><div>The development of high-performance oxygen evolution reaction catalysts with low iridium content is the key to the scale-up of proton exchange membrane water electrolyzer (PEMWE) for green hydrogen production. Single-site electrocatalysts with maximized atomic efficiency are held as promising candidates but still suffer from inadequate activity and stability in practical electrolyzer due to the low site density. Here, we proposed a NaNO<sub>3</sub>-assistant thermal decomposition strategy for the preparation of high-density Ir single sites on MnO<sub>2</sub> substrate (NaNO<sub>3</sub>-H-Ir-MnO<sub>2</sub>). Direct spectroscopic evidence suggests the inclusion of NaNO<sub>3</sub> accelerates the transformation of Ir-Cl to Ir-O coordination, thus generating uniform dispersed high-density Ir single sites in the products. The optimized H-Ir-MnO<sub>2</sub> demonstrates not only high intrinsic activity in a three-electrode set-up but also boosted performance in scalable PEMWE, requiring a cell voltage of only 1.74 V to attain a high current density of 2 A cm<sup>‒2</sup> at a low Ir loading of 0.18 mg<sub>Ir</sub> cm<sup>‒2</sup>. This work offers a new insight for enhancing the industrial practicality of Ir-based single site catalysts.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 223-232"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60137-3
Changshun Deng , Bingqing Ge , Jun Yao , Taotao Zhao , Chenyang Shen , Zhewei Zhang , Tao Wang , Xiangke Guo , Nianhua Xue , Xuefeng Guo , Luming Peng , Yan Zhu , Weiping Ding
The heterogeneous catalytic oxidation of toluene by O2 is an inherently safe and green route for production of benzaldehyde, but after more than fifty years of effort, it remains a great challenge. Here, we report the best heterogeneous catalyst, TeOx/MoVTeNbO, up to now for the green oxidation of toluene by O2 to benzaldehyde, balancing the catalyst activity, selectivity, and stability. The deposition of TeOx endows the MoVTeNbO composite oxide with entirely new property for toluene oxidation and the surface engineering mechanism has been fully explained. The discrete TeOx clusters on the surface, shielding the nonselective oxidation sites that interact strongly with the benzene ring of toluene molecule, allows toluene molecule to chemically adsorb to the surface perpendicularly and the methyl is then prone to oxidation to aldehyde on the reshaped selective oxidation sites, where V=O is the main active species responsible for continuously extracting hydrogen from methyl and implanting oxygen to form benzaldehyde. The TeOx clusters participate in this reaction through variable valences and stabilize benzaldehyde by couple interaction with the –CHO group of benzaldehyde, thereby achieving high selectivity to benzaldehyde (>95%). The extended works indicate that the catalytic mechanism is effective in a series of selective oxidation of toluene homologues to corresponding aldehydes.
{"title":"Surface engineering of TeOx modification on MoVTeNbO creates a high-performance catalyst for oxidation of toluene homologues to aldehydes","authors":"Changshun Deng , Bingqing Ge , Jun Yao , Taotao Zhao , Chenyang Shen , Zhewei Zhang , Tao Wang , Xiangke Guo , Nianhua Xue , Xuefeng Guo , Luming Peng , Yan Zhu , Weiping Ding","doi":"10.1016/S1872-2067(24)60137-3","DOIUrl":"10.1016/S1872-2067(24)60137-3","url":null,"abstract":"<div><div>The heterogeneous catalytic oxidation of toluene by O<sub>2</sub> is an inherently safe and green route for production of benzaldehyde, but after more than fifty years of effort, it remains a great challenge. Here, we report the best heterogeneous catalyst, TeO<sub><em>x</em></sub>/MoVTeNbO, up to now for the green oxidation of toluene by O<sub>2</sub> to benzaldehyde, balancing the catalyst activity, selectivity, and stability. The deposition of TeO<sub><em>x</em></sub> endows the MoVTeNbO composite oxide with entirely new property for toluene oxidation and the surface engineering mechanism has been fully explained. The discrete TeO<sub><em>x</em></sub> clusters on the surface, shielding the nonselective oxidation sites that interact strongly with the benzene ring of toluene molecule, allows toluene molecule to chemically adsorb to the surface perpendicularly and the methyl is then prone to oxidation to aldehyde on the reshaped selective oxidation sites, where V=O is the main active species responsible for continuously extracting hydrogen from methyl and implanting oxygen to form benzaldehyde. The TeO<sub><em>x</em></sub> clusters participate in this reaction through variable valences and stabilize benzaldehyde by couple interaction with the –CHO group of benzaldehyde, thereby achieving high selectivity to benzaldehyde (>95%). The extended works indicate that the catalytic mechanism is effective in a series of selective oxidation of toluene homologues to corresponding aldehydes.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 268-281"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60117-8
Jielin Huang , Jie Wang , Haonan Duan , Songsong Chen , Junping Zhang , Li Dong , Xiangping Zhang
Catalysts for CO2 value-added conversion have been extensively explored, but there is still a lack of systematic design for catalysts that achieve efficient CO2 conversion under mild conditions. Herein, we explored a mesoporous CeO2 single-crystal formed with the regulation of ionic liquids, which catalyzed the effective carbonylation reaction with CO2 under mild reaction conditions. By altering the synthetic environment, a series of uniform mesoporous CeO2 particles with atomically aligned single-crystal frameworks were constructed, which have different surface physicochemical properties and primary aggregation degree. The prepared mesoporous CeO2 single-crystal achieved efficient activation of CO2 and alcohols at 0.5 MPa CO2 and 100 °C, and the CeO2-IL-M catalyst shows optimal catalytic performance in the synthesis of ethylene carbonate with 46.22 mmol g–1 h–1, which was 50.6 times as high as that of the CeO2 obtained without ionic liquids. Subsequently, the catalytic pathway and mechanism of carbonylation reaction with CO2 on mesoporous CeO2 single-crystal were studied via React-IR spectra and C18O2 labeling experiments. The research provides a new strategy for controllable nanoscale assembly of mesoporous single-crystal materials and expands the application range of single-crystal materials, aiming to develop novel catalytic materials to meet industrial needs.
二氧化碳增值转化催化剂已被广泛探索，但在温和条件下实现二氧化碳高效转化的催化剂仍缺乏系统设计。在此，我们探索了一种在离子液体调节下形成的介孔 CeO2 单晶，它能在温和的反应条件下催化 CO2 的有效羰基化反应。通过改变合成环境，构建了一系列具有原子排列单晶框架的均匀介孔CeO2颗粒，它们具有不同的表面理化性质和初级聚集度。所制备的介孔 CeO2 单晶在 0.5 MPa CO2 和 100 ℃条件下实现了对 CO2 和醇类的高效活化，CeO2-IL-M 催化剂在合成碳酸乙烯酯中表现出最佳催化性能，其催化活性为 46.22 mmol g-1 h-1，是不含离子液体的 CeO2 催化剂的 50.6 倍。随后，通过 React-IR 光谱和 C18O2 标记实验研究了介孔 CeO2 单晶与 CO2 发生羰基化反应的催化途径和机理。该研究为介孔单晶材料的纳米尺度可控组装提供了新策略，拓展了单晶材料的应用范围，旨在开发新型催化材料以满足工业需求。
{"title":"Constructing mesoporous CeO2 single-crystal particles in ionic liquids for enhancing the conversion of CO2 and alcohols to carbonates","authors":"Jielin Huang , Jie Wang , Haonan Duan , Songsong Chen , Junping Zhang , Li Dong , Xiangping Zhang","doi":"10.1016/S1872-2067(24)60117-8","DOIUrl":"10.1016/S1872-2067(24)60117-8","url":null,"abstract":"<div><div>Catalysts for CO<sub>2</sub> value-added conversion have been extensively explored, but there is still a lack of systematic design for catalysts that achieve efficient CO<sub>2</sub> conversion under mild conditions. Herein, we explored a mesoporous CeO<sub>2</sub> single-crystal formed with the regulation of ionic liquids, which catalyzed the effective carbonylation reaction with CO<sub>2</sub> under mild reaction conditions. By altering the synthetic environment, a series of uniform mesoporous CeO<sub>2</sub> particles with atomically aligned single-crystal frameworks were constructed, which have different surface physicochemical properties and primary aggregation degree. The prepared mesoporous CeO<sub>2</sub> single-crystal achieved efficient activation of CO<sub>2</sub> and alcohols at 0.5 MPa CO<sub>2</sub> and 100 °C, and the CeO<sub>2</sub>-IL-M catalyst shows optimal catalytic performance in the synthesis of ethylene carbonate with 46.22 mmol g<sup>–1</sup> h<sup>–1</sup>, which was 50.6 times as high as that of the CeO<sub>2</sub> obtained without ionic liquids. Subsequently, the catalytic pathway and mechanism of carbonylation reaction with CO<sub>2</sub> on mesoporous CeO<sub>2</sub> single-crystal were studied <em>via</em> React-IR spectra and C<sup>18</sup>O<sub>2</sub> labeling experiments. The research provides a new strategy for controllable nanoscale assembly of mesoporous single-crystal materials and expands the application range of single-crystal materials, aiming to develop novel catalytic materials to meet industrial needs.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 152-167"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60140-3
Jinchang Xu , Yongqi Jian , Guang-Qiang Yu , Wanli Liang , Junmin Zhu , Muzi Yang , Jian Chen , Fangyan Xie , Yanshuo Jin , Nan Wang , Xi-Bo Li , Hui Meng
The underlying spin-related mechanism remains unclear, and the rational manipulation of spin states is challenging due to various spin configurations under different coordination conditions. Therefore, it is urgent to study spin-dependent oxygen evolution reaction (OER) performance through a controllable method. Herein, we adopt a topochemical reaction method to synthesize a series of selenides with eg occupancies ranging from 1.67 to 1.37. The process begins with monoclinic-CoSeO3, featuring a distinct laminar structure and Co-O6 coordination. The topochemical reaction induces significant changes in the crystal field's intensity, leading to spin state transitions. These transitions are driven by topological changes from a Co-O-Se-O-Co to a Co-Se-Co configuration, strengthening the crystalline field and reducing eg orbital occupancy. This reconfiguration of spin states shifts the rate-determining step from desorption to adsorption for both OER and the hydrogen evolution reaction (HER), reducing the potential-determined step barrier and enhancing overall catalytic efficiency. As a result, the synthesized cobalt selenide exhibits significantly enhanced adsorption capabilities. The material demonstrates impressive overpotentials of 35 mV for HER, 250 mV for OER, and 270 mV for overall water splitting, indicating superior catalytic activity and efficiency. Additionally, a negative relation between eg filling and OER catalytic performance confirms the spin-dependent nature of OER. Our findings provide crucial insights into the role of spin state transitions in catalytic performance.
由于不同配位条件下存在各种自旋构型，因此合理操纵自旋态具有挑战性。因此，通过可控方法研究自旋依赖的氧进化反应（OER）性能迫在眉睫。在此，我们采用拓扑化学反应方法合成了一系列eg占位从1.67到1.37的硒化物。合成过程从单斜-CoSeO3 开始，它具有独特的层状结构和 Co-O6 配位。拓扑化学反应会引起晶体场强度的显著变化，从而导致自旋态的转变。这些转变是由拓扑变化驱动的，从 Co-O-Se-O-Co 到 Co-Se-Co 构型，加强了晶体场，减少了 eg 轨道占用。自旋态的这种重新配置将 OER 和氢进化反应（HER）的速率决定步骤从解吸转移到吸附，从而降低了电位决定步骤障碍，提高了整体催化效率。因此，合成的硒化钴具有显著增强的吸附能力。该材料的 HER 过电位为 35 mV，OER 过电位为 250 mV，整体水分离过电位为 270 mV，显示出卓越的催化活性和效率。此外，eg 填充与 OER 催化性能之间的负相关关系证实了 OER 的自旋依赖性。我们的研究结果为了解自旋态转变在催化性能中的作用提供了重要启示。
{"title":"Manipulating the spin configuration by topochemical transformation for optimized intermediates adsorption ability in oxygen evolution reaction","authors":"Jinchang Xu , Yongqi Jian , Guang-Qiang Yu , Wanli Liang , Junmin Zhu , Muzi Yang , Jian Chen , Fangyan Xie , Yanshuo Jin , Nan Wang , Xi-Bo Li , Hui Meng","doi":"10.1016/S1872-2067(24)60140-3","DOIUrl":"10.1016/S1872-2067(24)60140-3","url":null,"abstract":"<div><div>The underlying spin-related mechanism remains unclear, and the rational manipulation of spin states is challenging due to various spin configurations under different coordination conditions. Therefore, it is urgent to study spin-dependent oxygen evolution reaction (OER) performance through a controllable method. Herein, we adopt a topochemical reaction method to synthesize a series of selenides with <em>e</em><sub>g</sub> occupancies ranging from 1.67 to 1.37. The process begins with monoclinic-CoSeO<sub>3</sub>, featuring a distinct laminar structure and Co-O<sub>6</sub> coordination. The topochemical reaction induces significant changes in the crystal field's intensity, leading to spin state transitions. These transitions are driven by topological changes from a Co-O-Se-O-Co to a Co-Se-Co configuration, strengthening the crystalline field and reducing <em>e</em><sub>g</sub> orbital occupancy. This reconfiguration of spin states shifts the rate-determining step from desorption to adsorption for both OER and the hydrogen evolution reaction (HER), reducing the potential-determined step barrier and enhancing overall catalytic efficiency. As a result, the synthesized cobalt selenide exhibits significantly enhanced adsorption capabilities. The material demonstrates impressive overpotentials of 35 mV for HER, 250 mV for OER, and 270 mV for overall water splitting, indicating superior catalytic activity and efficiency. Additionally, a negative relation between <em>e</em><sub>g</sub> filling and OER catalytic performance confirms the spin-dependent nature of OER. Our findings provide crucial insights into the role of spin state transitions in catalytic performance.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 195-211"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon supported Pt-based intermetallic compounds (IMCs) with high activity and durability are the most competitive cathode catalysts for the commercialization of proton exchange membrane fuel cells (PEMFCs). The synthesis of Pt-based intermetallics with a good balance between small size and high metal loading remains challenging because of the high-temperature annealing that is generally required to form intermetallic phases. We developed a sodium thiosulfate-assisted impregnation strategy to synthesize small-sized and highly ordered PtM IMCs catalysts (M = Co, Fe, Ni) with high-Pt-content (up to 44.5 wt%). During the impregnation process, thiosulfate could reduce H2PtCl6 to form uniformly dispersed Pt colloid on carbon supports, which in turn prevents the aggregation of Pt at the low-temperature annealing stage. Additionally, the strong interaction between Pt and S inhibits particle sintering, ensuring the formation of small-sized and uniform PtM intermetallic catalysts at the high-temperature annealing stage. The optimized intermetallic PtCo catalyst delivered a high mass activity of 0.72 A mgPt–1 and a large power performance of 1.17 W cm–2 at 0.65 V under H2-air conditions, along with 74% mass activity retention after the accelerated stress test.
具有高活性和耐久性的碳支撑铂基金属间化合物（IMC）是质子交换膜燃料电池（PEMFC）商业化过程中最具竞争力的阴极催化剂。由于形成金属间化合物相通常需要高温退火，因此合成兼顾小尺寸和高金属负载的铂基金属间化合物仍具有挑战性。我们开发了一种硫代硫酸钠辅助浸渍策略，用于合成高铂含量（高达 44.5 wt%）的小尺寸、高有序 PtM IMCs 催化剂（M = Co、Fe、Ni）。在浸渍过程中，硫代硫酸盐可以还原 H2PtCl6，在碳载体上形成均匀分散的铂胶体，从而防止铂在低温退火阶段聚集。此外，铂和 S 之间的强相互作用抑制了颗粒烧结，确保了在高温退火阶段形成小尺寸且均匀的 PtM 金属间化合物催化剂。优化后的金属间铂钴催化剂在氢空气条件下的质量活性高达 0.72 A mgPt-1，在 0.65 V 下的功率性能高达 1.17 W cm-2，并且在加速应力测试后的质量活性保持率为 74%。
{"title":"Sodium thiosulfate-assisted synthesis of high-Pt-content intermetallic electrocatalysts for fuel cells","authors":"Shi-Yi Yin , Shi-Long Xu , Zi-Rui Li , Shuai Li , Kun-Ze Xue , Wanqun Zhang , Sheng-Qi Chu , Hai-Wei Liang","doi":"10.1016/S1872-2067(24)60127-0","DOIUrl":"10.1016/S1872-2067(24)60127-0","url":null,"abstract":"<div><div>Carbon supported Pt-based intermetallic compounds (IMCs) with high activity and durability are the most competitive cathode catalysts for the commercialization of proton exchange membrane fuel cells (PEMFCs). The synthesis of Pt-based intermetallics with a good balance between small size and high metal loading remains challenging because of the high-temperature annealing that is generally required to form intermetallic phases. We developed a sodium thiosulfate-assisted impregnation strategy to synthesize small-sized and highly ordered Pt<em>M</em> IMCs catalysts (<em>M</em> = Co, Fe, Ni) with high-Pt-content (up to 44.5 wt%). During the impregnation process, thiosulfate could reduce H<sub>2</sub>PtCl<sub>6</sub> to form uniformly dispersed Pt colloid on carbon supports, which in turn prevents the aggregation of Pt at the low-temperature annealing stage. Additionally, the strong interaction between Pt and S inhibits particle sintering, ensuring the formation of small-sized and uniform Pt<em>M</em> intermetallic catalysts at the high-temperature annealing stage. The optimized intermetallic PtCo catalyst delivered a high mass activity of 0.72 A mg<sub>Pt</sub><sup>–1</sup> and a large power performance of 1.17 W cm<sup>–2</sup> at 0.65 V under H<sub>2</sub>-air conditions, along with 74% mass activity retention after the accelerated stress test.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 292-301"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60122-1
Shugang Sun , Yang Zhu , Letian Hong , Xuebing Li , Yu Gu , Hui Shi
Zeolites of *BEA framework topology containing isomorphously substituted Lewis acidic metal centers catalyze the liquid-phase intramolecular Prins cyclization of citronellal with outstanding catalytic activity and (dia-)stereoselectivity to the commercially most valuable product, isopulegol (IPL). Effects of the metal-center identity and solvent type were occasionally noted, yet without systematic studies hitherto reported. Here, characteristic dependences of catalytic activities and stereoselectivities on solvent and metal identity were uncovered over four M(IV)-Beta catalysts (M = Sn, Ti, Zr and Hf) in four distinct solvents (i.e., acetonitrile, tert-butanol, cyclohexane and n-hexane). Zr- and Hf-Beta were the most active in acetonitrile and the most selective (> 90% to IPL) in tert-butanol, though their activities were generally lower than Ti- and Sn-Beta in solvents other than acetonitrile. By comparison, Ti-Beta was inferior to other catalysts in terms of both activity and IPL selectivity (as previously shown) in acetonitrile but became the most active in other solvents, with markedly increased IPL selectivity from 60% to 70%‒80%. Combining multiple site discrimination and quantification techniques, turnover frequencies were determined for the first time in this reaction; such site-based activities, coupled with comprehensive kinetic interrogations, not only enabled a rigorous comparison of catalytic activities across M-Beta catalysts but also provided deeper insights into the free energy driving forces as solvent and metal identity are varied. The activity and selectivity trends, as well as those for the adsorption and intrinsic activation parameters are caused by solvent co-binding at the active site (acetonitrile and tert-butanol) and less quantifiable crowding effects (cyclohexane) due to the limited pore space and the need to accommodate relatively bulky reactant-derived moieties. This work exemplifies how the interplay of metal identity and solvent determines the reactivities and selectivities in Lewis-acid-catalyzed reactions within confined spaces.
{"title":"Interplay of solvent and metal identity determines rates and stereoselectivities in M(IV)-Beta-catalyzed intramolecular Prins cyclization of citronellal","authors":"Shugang Sun , Yang Zhu , Letian Hong , Xuebing Li , Yu Gu , Hui Shi","doi":"10.1016/S1872-2067(24)60122-1","DOIUrl":"10.1016/S1872-2067(24)60122-1","url":null,"abstract":"<div><div>Zeolites of *BEA framework topology containing isomorphously substituted Lewis acidic metal centers catalyze the liquid-phase intramolecular Prins cyclization of citronellal with outstanding catalytic activity and (dia-)stereoselectivity to the commercially most valuable product, isopulegol (IPL). Effects of the metal-center identity and solvent type were occasionally noted, yet without systematic studies hitherto reported. Here, characteristic dependences of catalytic activities and stereoselectivities on solvent and metal identity were uncovered over four <em>M</em>(IV)-Beta catalysts (<em>M</em> = Sn, Ti, Zr and Hf) in four distinct solvents (i.e., acetonitrile, tert-butanol, cyclohexane and <em>n</em>-hexane). Zr- and Hf-Beta were the most active in acetonitrile and the most selective (> 90% to IPL) in tert-butanol, though their activities were generally lower than Ti- and Sn-Beta in solvents other than acetonitrile. By comparison, Ti-Beta was inferior to other catalysts in terms of both activity and IPL selectivity (as previously shown) in acetonitrile but became the most active in other solvents, with markedly increased IPL selectivity from 60% to 70%‒80%. Combining multiple site discrimination and quantification techniques, turnover frequencies were determined for the first time in this reaction; such site-based activities, coupled with comprehensive kinetic interrogations, not only enabled a rigorous comparison of catalytic activities across M-Beta catalysts but also provided deeper insights into the free energy driving forces as solvent and metal identity are varied. The activity and selectivity trends, as well as those for the adsorption and intrinsic activation parameters are caused by solvent co-binding at the active site (acetonitrile and tert-butanol) and less quantifiable crowding effects (cyclohexane) due to the limited pore space and the need to accommodate relatively bulky reactant-derived moieties. This work exemplifies how the interplay of metal identity and solvent determines the reactivities and selectivities in Lewis-acid-catalyzed reactions within confined spaces.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 233-246"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60120-8
Xiaotian Wang, Bo Hu, Yuan Li, Zhixiong Yang, Gaoke Zhang
The low efficiency of photogenerated carrier separation, and the poor adsorption and activation ability of CO2 on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO2 reduction. Hence, maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO2 reduction. However, it is still huge challenge. In this work, the Ni-doped ultrathin Bi4O5Br2 nanosheets, which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods, exhibited efficient photocatalytic conversion of CO2 to CO. The results of experiments and theoretical calculations indicated that the doped Ni2+ significantly increased the crystal dipole moment of Bi4O5Br2 in y direction (from 0 to 0.096 eÅ), which enhanced the polarized electric field strength inside Bi4O5Br2, and further promoted the immigration of photogenerated carriers. Meanwhile, the ultrathin structure and doped Ni2+ synergistically increased the number of active sites, thereby promoting the adsorption and activation of CO2 molecules, as evidenced by experimental and theoretical results collectively. As result, The CO yield was as high as 26.57 μmol g–1 h–1 for the prepared Ni-doped ultrathin Bi4O5Br2 nanosheets under full spectrum light irradiation, which was 9.48 times that of Bi4O5Br2. Therefore, it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO2 on the surface.
光生载流子分离效率低、光催化剂表面对二氧化碳的吸附和活化能力差是限制光催化还原二氧化碳效率的关键问题。因此，最大限度地加速光生电荷的迁移和增加活性位点的数量是提高光催化还原二氧化碳整体性能的关键点。然而，这仍然是一个巨大的挑战。本研究采用水热法和超声波化学剥离法成功制备了掺镍超薄Bi4O5Br2纳米片，该纳米片具有将CO2高效光催化转化为CO的性能。实验和理论计算结果表明，掺杂的Ni2+显著增加了Bi4O5Br2在y方向上的晶体偶极矩（从0增至0.096埃），从而增强了Bi4O5Br2内部的极化电场强度，进一步促进了光生载流子的迁移。同时，超薄结构和掺杂 Ni2+ 协同增加了活性位点的数量，从而促进了 CO2 分子的吸附和活化。结果表明，在全光谱光照射下，制备的掺镍超薄 Bi4O5Br2 纳米片的 CO 产率高达 26.57 μmol g-1 h-1，是 Bi4O5Br2 的 9.48 倍。因此，本研究探索促进光生载流子分离、增强表面对 CO2 的吸附和活化能力的策略具有重要的科学意义。
{"title":"Dipole moment regulation by Ni doping ultrathin Bi4O5Br2 for enhancing internal electric field toward efficient photocatalytic conversion of CO2 to CO","authors":"Xiaotian Wang, Bo Hu, Yuan Li, Zhixiong Yang, Gaoke Zhang","doi":"10.1016/S1872-2067(24)60120-8","DOIUrl":"10.1016/S1872-2067(24)60120-8","url":null,"abstract":"<div><div>The low efficiency of photogenerated carrier separation, and the poor adsorption and activation ability of CO<sub>2</sub> on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO<sub>2</sub> reduction. Hence, maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO<sub>2</sub> reduction. However, it is still huge challenge. In this work, the Ni-doped ultrathin Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> nanosheets, which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods, exhibited efficient photocatalytic conversion of CO<sub>2</sub> to CO. The results of experiments and theoretical calculations indicated that the doped Ni<sup>2+</sup> significantly increased the crystal dipole moment of Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> in <em>y</em> direction (from 0 to 0.096 eÅ), which enhanced the polarized electric field strength inside Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>, and further promoted the immigration of photogenerated carriers. Meanwhile, the ultrathin structure and doped Ni<sup>2+</sup> synergistically increased the number of active sites, thereby promoting the adsorption and activation of CO<sub>2</sub> molecules, as evidenced by experimental and theoretical results collectively. As result, The CO yield was as high as 26.57 μmol g<sup>–1</sup> h<sup>–1</sup> for the prepared Ni-doped ultrathin Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> nanosheets under full spectrum light irradiation, which was 9.48 times that of Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>. Therefore, it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO<sub>2</sub> on the surface.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 257-267"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60125-7
Junbao Peng , Jin Xie , Zelong Li , Can Li
Substituted ureas hold considerable significance in both natural and synthetic chemicals. Pd-based homogenous catalyst has been used for the urea synthesis, however the aggregation of Pd(0) species leads to the deactivation of the catalyst even under mild conditions. Here, we present a photon-involved carbonylation of amines to synthesize ureas, achieving product yields of up to 99%, using Pd(OAc)2 and KI without losing the performance owing to the fast regeneration of Pd species under light irradiation. Reaction kinetics results and ultraviolet-visible absorption spectra indicate the regeneration of the Pd species is realized by the light irradiation (below 450 nm) which induces the oxidation reaction between HI and O2 to produce I2, so that the active species PdI2 is regenerated through the reaction between Pd(0) and the I2.
{"title":"Photon-induced regeneration of Pd catalyst for carbonylation of amines to ureas","authors":"Junbao Peng , Jin Xie , Zelong Li , Can Li","doi":"10.1016/S1872-2067(24)60125-7","DOIUrl":"10.1016/S1872-2067(24)60125-7","url":null,"abstract":"<div><div>Substituted ureas hold considerable significance in both natural and synthetic chemicals. Pd-based homogenous catalyst has been used for the urea synthesis, however the aggregation of Pd(0) species leads to the deactivation of the catalyst even under mild conditions. Here, we present a photon-involved carbonylation of amines to synthesize ureas, achieving product yields of up to 99%, using Pd(OAc)<sub>2</sub> and KI without losing the performance owing to the fast regeneration of Pd species under light irradiation. Reaction kinetics results and ultraviolet-visible absorption spectra indicate the regeneration of the Pd species is realized by the light irradiation (below 450 nm) which induces the oxidation reaction between HI and O<sub>2</sub> to produce I<sub>2</sub>, so that the active species PdI<sub>2</sub> is regenerated through the reaction between Pd(0) and the I<sub>2</sub>.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 146-151"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60130-0
Wangyang Wu , Shidan Yang , Huidan Qian , Ling Zhang , Lishan Peng , Li Li , Bin Liu , Zidong Wei
Developing efficient, stable, and low-cost electrocatalysts toward alkaline hydrogen evolution reactions (HER) in water electrolysis driven by renewable energy sources has always been discussed over the past decade. To reduce energy consumption and improve energy utilization efficiency, highly active electrocatalytic electrodes are essential for lowering the energy barrier of the HER. Catalysts featuring multiple interfaces have attracted significant research interest recently due to their enhanced physicochemical properties. Reasonable interface modulation can optimize intermediate active species’ adsorption energy, improve catalytic active sites’ selectivity, and enhance intrinsic catalytic activity. Here, we provided an overview of the latest advancement in interface engineering for efficient HER catalysts. We begin with a brief introduction to the fundamental concepts and mechanisms of alkaline HER. Then, we analyze and discuss current regulating principles in interface engineering for HER catalysts, focusing particularly on optimizing electron structures and modulating microenvironment reactions. Finally, the challenges and further prospects of interface catalysts for future applications are discussed.
过去十年来，人们一直在讨论开发高效、稳定和低成本的电催化剂，用于可再生能源驱动的水电解过程中的碱性氢进化反应（HER）。为了降低能耗和提高能源利用效率，高活性电催化电极对于降低氢进化反应的能量障碍至关重要。具有多个界面的催化剂因其增强的物理化学特性而在最近引起了极大的研究兴趣。合理的界面调控可以优化中间活性物种的吸附能，提高催化活性位点的选择性，增强内在催化活性。在此，我们概述了高效 HER 催化剂界面工程的最新进展。我们首先简要介绍了碱性 HER 的基本概念和机理。然后，我们分析并讨论了当前 HER 催化剂界面工程的调节原则，尤其侧重于优化电子结构和调节微环境反应。最后，我们讨论了界面催化剂在未来应用中面临的挑战和进一步的发展前景。
{"title":"Interface engineering of advanced electrocatalysts toward alkaline hydrogen evolution reactions","authors":"Wangyang Wu , Shidan Yang , Huidan Qian , Ling Zhang , Lishan Peng , Li Li , Bin Liu , Zidong Wei","doi":"10.1016/S1872-2067(24)60130-0","DOIUrl":"10.1016/S1872-2067(24)60130-0","url":null,"abstract":"<div><div>Developing efficient, stable, and low-cost electrocatalysts toward alkaline hydrogen evolution reactions (HER) in water electrolysis driven by renewable energy sources has always been discussed over the past decade. To reduce energy consumption and improve energy utilization efficiency, highly active electrocatalytic electrodes are essential for lowering the energy barrier of the HER. Catalysts featuring multiple interfaces have attracted significant research interest recently due to their enhanced physicochemical properties. Reasonable interface modulation can optimize intermediate active species’ adsorption energy, improve catalytic active sites’ selectivity, and enhance intrinsic catalytic activity. Here, we provided an overview of the latest advancement in interface engineering for efficient HER catalysts. We begin with a brief introduction to the fundamental concepts and mechanisms of alkaline HER. Then, we analyze and discuss current regulating principles in interface engineering for HER catalysts, focusing particularly on optimizing electron structures and modulating microenvironment reactions. Finally, the challenges and further prospects of interface catalysts for future applications are discussed.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 1-19"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/S1872-2067(24)60133-6
Hao Liu , Bingxian Chu , Tianxiang Chen , Jie Zhou , Lihui Dong , Tsz Woon Benedict Lo , Bin Li , Xiaohui He , Hongbing Ji
Dispersing metals from nanoparticles into clusters or single atoms often exhibits unique properties such as the inhibition of structure-sensitive side reactions. Here, we reported the use of ion exchange (IE) methods and direct hydrogen reduction to achieve high dispersion of Co species on zincosilicate. The obtained 2Co/Zn-4-IE catalyst achieved an initial propane conversion of 41.4% at a temperature of 550 °C in a 25% propane and 75% nitrogen atmosphere for propane dehydrogenation. Visualization of the presence of Co species within specific rings (alpha-α, beta-β and delta-δ) was obtained by aberration-corrected scanning transmission electron microscopy. A series of Fourier transform infrared spectra confirmed the anchoring of Co by specific hydroxyl groups in zincosilicate and the specific coordination environment of Co and its presence in the rings essentially as a single site. The framework Zn for the modulation of the microenvironment and the presence of Co species as Lewis acid active sites (Co-O4) was also supported by density functional theory calculations.
将金属从纳米颗粒分散成团簇或单原子通常会表现出独特的特性，例如抑制结构敏感的副反应。在此，我们报告了使用离子交换（IE）方法和直接氢还原法在硅酸锌上实现 Co 物种的高度分散。获得的 2Co/Zn-4-IE 催化剂在 25% 丙烷和 75% 氮气气氛中进行 550 °C 丙烷脱氢反应时，丙烷的初始转化率为 41.4%。通过像差校正扫描透射电子显微镜观察到了特定环（α-α、β-β 和 delta-δ）中 Co 物种的存在。一系列傅立叶变换红外光谱证实了硅酸锌中特定羟基对 Co 的锚定作用，以及 Co 的特定配位环境和它在环中基本上作为单一位点的存在。密度泛函理论计算也证实了 Zn 框架对微环境的调节作用以及 Co 物种作为路易斯酸活性位点（Co-O4）的存在。
{"title":"Modulation of the cobalt species state on zincosilicate to maximize propane dehydrogenation to propylene","authors":"Hao Liu , Bingxian Chu , Tianxiang Chen , Jie Zhou , Lihui Dong , Tsz Woon Benedict Lo , Bin Li , Xiaohui He , Hongbing Ji","doi":"10.1016/S1872-2067(24)60133-6","DOIUrl":"10.1016/S1872-2067(24)60133-6","url":null,"abstract":"<div><div>Dispersing metals from nanoparticles into clusters or single atoms often exhibits unique properties such as the inhibition of structure-sensitive side reactions. Here, we reported the use of ion exchange (IE) methods and direct hydrogen reduction to achieve high dispersion of Co species on zincosilicate. The obtained 2Co/Zn-4-IE catalyst achieved an initial propane conversion of 41.4% at a temperature of 550 °C in a 25% propane and 75% nitrogen atmosphere for propane dehydrogenation. Visualization of the presence of Co species within specific rings (alpha-α, beta-β and delta-δ) was obtained by aberration-corrected scanning transmission electron microscopy. A series of Fourier transform infrared spectra confirmed the anchoring of Co by specific hydroxyl groups in zincosilicate and the specific coordination environment of Co and its presence in the rings essentially as a single site. The framework Zn for the modulation of the microenvironment and the presence of Co species as Lewis acid active sites (Co-O<sub>4</sub>) was also supported by density functional theory calculations.</div></div>","PeriodicalId":9832,"journal":{"name":"Chinese Journal of Catalysis","volume":"66 ","pages":"Pages 168-180"},"PeriodicalIF":15.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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