Pub Date : 2024-06-25DOI: 10.1021/acscatal.3c04275
Hyun-Tak Kim, Jaehyun Park, Jinhong Mun, HyeonOh Shin, Deok-Ho Roh, Junhyeok Kwon, Sungtae Kim, Sang-Joon Kim, Geunsik Lee, Seok Ju Kang, Tae-Hyuk Kwon
Efficient electroreduction of CO2 to multicarbon products is a complicated reaction because of the high energy barriers for the CO2 activation and C–C coupling. Here, we design a graphitic frustrated Lewis pair catalyst doped with boron and nitrogen (BN-GFLP) for reducing the amount of CO2 to multicarbon products. Multicarbon (C2+) biofuels (i.e., ethanol and n-propanol) are identified as the major products with a C2+ Faradaic efficiency of 87.9% at a partial current density of −6.0 mA/cm2 (C2+ Faradaic efficiency of 70.7% at a partial current density of −10.6 mA/cm2). Furthermore, density functional theory calculations reveal that the dual binding site of FLP reduces the reaction free energies required for CO2 activation and C–C coupling. Consequently, energetically favorable CO2 reduction pathways are proposed, and selectivities for the production of ethanol and n-propanol are determined. Based on our results, we propose a molecular design strategy for the selective CO2 reduction catalysts aimed at facilitating C2+ alcohols production.
{"title":"Selective Electroreduction of CO2 to C2+ Alcohols Using Graphitic Frustrated Lewis Pair Catalyst","authors":"Hyun-Tak Kim, Jaehyun Park, Jinhong Mun, HyeonOh Shin, Deok-Ho Roh, Junhyeok Kwon, Sungtae Kim, Sang-Joon Kim, Geunsik Lee, Seok Ju Kang, Tae-Hyuk Kwon","doi":"10.1021/acscatal.3c04275","DOIUrl":"https://doi.org/10.1021/acscatal.3c04275","url":null,"abstract":"Efficient electroreduction of CO<sub>2</sub> to multicarbon products is a complicated reaction because of the high energy barriers for the CO<sub>2</sub> activation and C–C coupling. Here, we design a graphitic frustrated Lewis pair catalyst doped with boron and nitrogen (BN-GFLP) for reducing the amount of CO<sub>2</sub> to multicarbon products. Multicarbon (C<sub>2+</sub>) biofuels (i.e., ethanol and <i>n</i>-propanol) are identified as the major products with a C<sub>2+</sub> Faradaic efficiency of 87.9% at a partial current density of −6.0 mA/cm<sup>2</sup> (C<sub>2+</sub> Faradaic efficiency of 70.7% at a partial current density of −10.6 mA/cm<sup>2</sup>). Furthermore, density functional theory calculations reveal that the dual binding site of FLP reduces the reaction free energies required for CO<sub>2</sub> activation and C–C coupling. Consequently, energetically favorable CO<sub>2</sub> reduction pathways are proposed, and selectivities for the production of ethanol and <i>n</i>-propanol are determined. Based on our results, we propose a molecular design strategy for the selective CO<sub>2</sub> reduction catalysts aimed at facilitating C<sub>2+</sub> alcohols production.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461560","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}
Direct reduction of low-concentration CO2 from exhaust gases (3–13%) is important for CO2 utilization technologies because CO2 condensation processes require high energy consumption and cost. The Re(I) ethoxide complex fac-[Re(bpy-CH2OH)(CO)3(OEt)] (bpy-CH2OH = 4,4′-bis(hydroxymethyl)-2,2′-bipyridine), which is formed in an EtOH solution containing a base, efficiently captured CO2 to form the carbonate-ester complex fac-[Re(bpy-CH2OH)(CO)3(OCOOEt)] (Re(OCOOEt)) under both 10% and 100% CO2 atmospheres. In an EtOH solution containing 1,1,3,3-tetramethylguanidine (TMG) as the base, the electrocatalytic CO2 reduction reaction proceeded by Re(OCOOEt) with high CO selectivity, Faradaic efficiency, and durability even under a 10% CO2 atmosphere. This high electrocatalysis was retained in the presence of water in the solution up to 2.8 M (5 vol %). On the other hand, the electrocatalytic CO2 reduction reaction did not proceed efficiently in the absence of TMG under 10% CO2. The mechanistic studies and investigation suggest that the formation of the carbonate-ester complex in advance is necessary for the highly efficient electrocatalytic reduction of low-concentration CO2 in EtOH.
直接还原废气中的低浓度二氧化碳（3%-13%）对二氧化碳利用技术非常重要，因为二氧化碳冷凝过程需要高能耗和高成本。在含有碱的 EtOH 溶液中形成的 Re(I)乙氧化物复合物 fac-[Re(bpy-CH2OH)(CO)3(OEt)]（bpy-CH2OH = 4,4′-双（羟甲基）-2,2′-联吡啶）能有效捕获二氧化碳，形成碳酸酯复合物、在 10% 和 100% CO2 的气氛下，都能有效捕获 CO2，形成碳酸酯复合物 fac-[Re(bpy-CH2OH)(CO)3(OCOOEt)] (Re(OCOOEt))。在含有 1,1,3,3-四甲基胍 (TMG) 作为碱的 EtOH 溶液中，Re(OCOOEt) 进行的电催化 CO2 还原反应即使在 10% CO2 的气氛下也具有很高的 CO 选择性、法拉第效率和持久性。即使溶液中含有高达 2.8 M（5 vol %）的水，这种高电催化性能也能保持。另一方面，在没有 TMG 的情况下，电催化二氧化碳还原反应在 10% CO2 的环境下也不能有效进行。机理研究和调查表明，要在 EtOH 中高效电催化还原低浓度 CO2，必须事先形成碳酸酯复合物。
{"title":"CO2 Capture and Electrochemical Reduction of Low-Concentration CO2 Using a Re(I)-Complex Catalyst in Ethanol","authors":"Masahiko Miyaji, Yusuke Tamaki, Kei Kamogawa, Yuto Abiru, Manabu Abe, Osamu Ishitani","doi":"10.1021/acscatal.4c01120","DOIUrl":"https://doi.org/10.1021/acscatal.4c01120","url":null,"abstract":"Direct reduction of low-concentration CO<sub>2</sub> from exhaust gases (3–13%) is important for CO<sub>2</sub> utilization technologies because CO<sub>2</sub> condensation processes require high energy consumption and cost. The Re(I) ethoxide complex <i>fac</i>-[Re(bpy-CH<sub>2</sub>OH)(CO)<sub>3</sub>(OEt)] (bpy-CH<sub>2</sub>OH = 4,4′-bis(hydroxymethyl)-2,2′-bipyridine), which is formed in an EtOH solution containing a base, efficiently captured CO<sub>2</sub> to form the carbonate-ester complex <i>fac</i>-[Re(bpy-CH<sub>2</sub>OH)(CO)<sub>3</sub>(OCOOEt)] (<b>Re(OCOOEt)</b>) under both 10% and 100% CO<sub>2</sub> atmospheres. In an EtOH solution containing 1,1,3,3-tetramethylguanidine (TMG) as the base, the electrocatalytic CO<sub>2</sub> reduction reaction proceeded by <b>Re(OCOOEt)</b> with high CO selectivity, Faradaic efficiency, and durability even under a 10% CO<sub>2</sub> atmosphere. This high electrocatalysis was retained in the presence of water in the solution up to 2.8 M (5 vol %). On the other hand, the electrocatalytic CO<sub>2</sub> reduction reaction did not proceed efficiently in the absence of TMG under 10% CO<sub>2</sub>. The mechanistic studies and investigation suggest that the formation of the carbonate-ester complex in advance is necessary for the highly efficient electrocatalytic reduction of low-concentration CO<sub>2</sub> in EtOH.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461622","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 : 2024-06-25DOI: 10.1021/acscatal.4c02548
Caterina Trotta, Gabriel Menendez Rodriguez, Cristiano Zuccaccia, Alceo Macchioni
Although there is a huge interest in redox mediators for the selective electrochemical regeneration of 1,4-NADH, only the class of rhodium compounds with bipyridine ligands, initially introduced by the pioneering work of Wienkamp and Steckhan (Wienkamp, R.; Steckhan, E.Angew. Chem. Int. Ed. Engl.1982, 21, 782−783, 10.1002/anie.198207822), has been developed over the last few decades. Here we report the first two progenitors of a class of redox mediators for indirect NADH regeneration, namely [Cp*Ir(R′-pica)Cl] {pica = R′-picolinamidate = κ2-R′-pyridine-2-carboxamide ion (−1), 1 R′ = H and 2 R′ = Me}, which exhibit high TOF values (0.51 and 1.34 s–1 for 1 and 2, respectively), a production rate of up to 3 μmol h–1 cm–2, and a faradaic efficiency of up to 99% for both complexes in 0.1 M phosphate buffer (pH 7, 298 K). The reaction exclusively leads to a mixture of 1,4-NADH, the desired product, and 1,6-NADH always in a 91:9 molar ratio, independently of the redox mediator, degree of conversion, and applied potential. 1H EXSY NMR unequivocally shows that a rapid equilibrium establishes between 1,6-NADH and 1,4-NADH (Keq = 10.1, ΔG0 = −1.4 kcal mol–1, 298 K), in the presence of 1 and 2, suggesting that the latter are capable of rapidly interconverting the two regioisomers of NADH, thus allowing utilization of the totality of regenerated NADH.
{"title":"Electrochemical NADH Regeneration Mediated by Pyridine Amidate Iridium Complexes Interconverting 1,4- and 1,6-NADH","authors":"Caterina Trotta, Gabriel Menendez Rodriguez, Cristiano Zuccaccia, Alceo Macchioni","doi":"10.1021/acscatal.4c02548","DOIUrl":"https://doi.org/10.1021/acscatal.4c02548","url":null,"abstract":"Although there is a huge interest in redox mediators for the selective electrochemical regeneration of 1,4-NADH, only the class of rhodium compounds with bipyridine ligands, initially introduced by the pioneering work of Wienkamp and Steckhan (<contrib-group><span>Wienkamp, R.</span>; <span>Steckhan, E.</span></contrib-group> <cite><i>Angew. Chem. Int. Ed. Engl.</i></cite> <span>1982</span>, <em>21</em>, 782−783, 10.1002/anie.198207822</pub-id>), has been developed over the last few decades. Here we report the first two progenitors of a class of redox mediators for indirect NADH regeneration, namely [Cp*Ir(R′-pica)Cl] {pica = R′-picolinamidate = κ<sup>2</sup>-R′-pyridine-2-carboxamide ion (−1), <b>1</b> R′ = H and <b>2</b> R′ = Me}, which exhibit high TOF values (0.51 and 1.34 s<sup>–1</sup> for <b>1</b> and <b>2</b>, respectively), a production rate of up to 3 μmol h<sup>–1</sup> cm<sup>–2</sup>, and a faradaic efficiency of up to 99% for both complexes in 0.1 M phosphate buffer (pH 7, 298 K). The reaction exclusively leads to a mixture of 1,4-NADH, the desired product, and 1,6-NADH always in a 91:9 molar ratio, independently of the redox mediator, degree of conversion, and applied potential. <sup>1</sup>H EXSY NMR unequivocally shows that a rapid equilibrium establishes between 1,6-NADH and 1,4-NADH (<i>K</i><sub>eq</sub> = 10.1, Δ<i>G</i><sup>0</sup> = −1.4 kcal mol<sup>–1</sup>, 298 K), in the presence of <b>1</b> and <b>2</b>, suggesting that the latter are capable of rapidly interconverting the two regioisomers of NADH, thus allowing utilization of the totality of regenerated NADH.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448846","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 : 2024-06-25DOI: 10.1021/acscatal.4c02979
Yunhao Liu, Xincheng Li, Qingpeng Cheng, Ye Tian, Yingtian Zhang, Tong Ding, Song Song, Kepeng Song, Xingang Li
The sintering of metal catalysts caused by Ostwald ripening (OR) and particle migration and coalescence (PMC) is one of the major challenges in heterogeneous catalysis. Here, we develop an efficient Ru catalyst supported on hydrophobic carbon-encapsulated TiO2 for Fischer–Tropsch synthesis (FTS). Combining comprehensive characterizations, we discover that hydrophobic carbon layers predominantly obstruct OR, and appropriate metal–support interactions avoid PMC. The dual effects collectively prevent the aggregation and sintering of diminutive Ru nanoparticles (NPs) during the FTS process and induce robust catalytic performance. Moreover, this unique structure exposes more Ru sites to promote CO hydrogenation and diminishes Ru-TiO2 interfaces to adsorb more *CO and fewer *H species, which facilitates the production of longer-chain hydrocarbons. Consequently, at 220 °C, our catalyst exhibits a superior turnover frequency (TOF) of 0.189 s–1 and a Ru time yield of 2.67 molCO gRu–1 h–1, surpassing those of the reported Ru-based catalysts. Simultaneously, the catalyst shows a C5+ selectivity of 85.3% and is particularly effective in producing C15+ (soft paraffin), with a selectivity of 57.3%. Our catalyst design strategy holds promise for efficient catalytic processes in various industrial applications.
{"title":"Efficient and Stable Production of Long-Chain Hydrocarbons over Hydrophobic Carbon-Encapsulated TiO2-Supported Ru Catalyst in Fischer–Tropsch Synthesis","authors":"Yunhao Liu, Xincheng Li, Qingpeng Cheng, Ye Tian, Yingtian Zhang, Tong Ding, Song Song, Kepeng Song, Xingang Li","doi":"10.1021/acscatal.4c02979","DOIUrl":"https://doi.org/10.1021/acscatal.4c02979","url":null,"abstract":"The sintering of metal catalysts caused by Ostwald ripening (OR) and particle migration and coalescence (PMC) is one of the major challenges in heterogeneous catalysis. Here, we develop an efficient Ru catalyst supported on hydrophobic carbon-encapsulated TiO<sub>2</sub> for Fischer–Tropsch synthesis (FTS). Combining comprehensive characterizations, we discover that hydrophobic carbon layers predominantly obstruct OR, and appropriate metal–support interactions avoid PMC. The dual effects collectively prevent the aggregation and sintering of diminutive Ru nanoparticles (NPs) during the FTS process and induce robust catalytic performance. Moreover, this unique structure exposes more Ru sites to promote CO hydrogenation and diminishes Ru-TiO<sub>2</sub> interfaces to adsorb more *CO and fewer *H species, which facilitates the production of longer-chain hydrocarbons. Consequently, at 220 °C, our catalyst exhibits a superior turnover frequency (<i>TOF</i>) of 0.189 s<sup>–1</sup> and a Ru time yield of 2.67 mol<sub>CO</sub> g<sub>Ru</sub><sup>–1</sup> h<sup>–1</sup>, surpassing those of the reported Ru-based catalysts. Simultaneously, the catalyst shows a C<sub>5+</sub> selectivity of 85.3% and is particularly effective in producing C<sub>15+</sub> (soft paraffin), with a selectivity of 57.3%. Our catalyst design strategy holds promise for efficient catalytic processes in various industrial applications.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461746","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 : 2024-06-25DOI: 10.1021/acscatal.4c01150
Jihun Kang, Balaji G. Ghule, Seung Gyu Gyeong, Seong-Ji Ha, Ji-Hyun Jang
Hematite (Fe2O3) is a promising photoanode for photoelectrochemical (PEC) water splitting, yet its performance is hindered by low electrical conductivity and charge recombination. Phosphorus (P) doping into hematite has been highlighted for its potential to enhance conductivity and minimize recombination by preventing electron trapping through P5+ states. Despite the interest in P doping to improve hematite photoanodes, establishing an effective P-doping synthesis remains challenging, often resulting in suboptimal PEC outcomes. In this study, we identify that unintentional tin (Sn) diffusion from the fluorine-doped tin oxide (FTO) substrate significantly impacts P-doped Fe2O3 performance. Addressing the detrimental interaction between unintentional Sn4+ and intentional P5+ dopants, we introduce titanium (Ti) as a guest dopant to mitigate dopant repulsion. The resulting P:Sn:Ti–Fe2O3 exhibits a 4-fold increase in photocurrent density to 3.44 mA cm–2 at 1.23 VRHE, marking a significant advancement in P-doped hematite research. With a NiFeOx cocatalyst, the NiFeOx/P:Sn:Ti–Fe2O3 photoanode further reaches a peak photocurrent density of 4.30 mA cm–2 at 1.23 VRHE. Our findings, both experimental and computational, demonstrate that overcoming negative dopant interactions is crucial for enhancing PEC performance and ensuring the photoanode’s thermodynamic stability.
赤铁矿（Fe2O3）是一种很有前途的光电化学（PEC）分水光阳极，但其性能却受到低电导率和电荷重组的阻碍。在赤铁矿中掺入磷（P），通过防止 P5+态的电子捕获，从而提高导电性并最大限度地减少电荷重组，这一点已受到重视。尽管人们对通过掺入 P 来改善赤铁矿光阳极很感兴趣，但建立有效的 P 掺杂合成方法仍具有挑战性，这往往会导致 PEC 结果不理想。在本研究中，我们发现从掺氟氧化锡（FTO）基底无意扩散的锡（Sn）会严重影响掺杂 P 的 Fe2O3 的性能。为了解决无意的 Sn4+ 和有意的 P5+ 掺杂剂之间的有害相互作用，我们引入了钛（Ti）作为客体掺杂剂，以减轻掺杂剂的排斥作用。由此产生的 P:Sn:Ti-Fe2O3 在 1.23 VRHE 下的光电流密度增加了 4 倍，达到 3.44 mA cm-2，标志着掺杂 P 的赤铁矿研究取得了重大进展。有了 NiFeOx 助催化剂，NiFeOx/P:Sn:Ti-Fe2O3 光阳极在 1.23 VRHE 时的峰值光电流密度进一步达到 4.30 mA cm-2。我们的实验和计算结果表明，克服负掺杂相互作用对于提高 PEC 性能和确保光阳极的热力学稳定性至关重要。
{"title":"Alleviating Charge Recombination Caused by Unfavorable interaction of P and Sn in Hematite for Photoelectrochemical Water Oxidation","authors":"Jihun Kang, Balaji G. Ghule, Seung Gyu Gyeong, Seong-Ji Ha, Ji-Hyun Jang","doi":"10.1021/acscatal.4c01150","DOIUrl":"https://doi.org/10.1021/acscatal.4c01150","url":null,"abstract":"Hematite (Fe<sub>2</sub>O<sub>3</sub>) is a promising photoanode for photoelectrochemical (PEC) water splitting, yet its performance is hindered by low electrical conductivity and charge recombination. Phosphorus (P) doping into hematite has been highlighted for its potential to enhance conductivity and minimize recombination by preventing electron trapping through P<sup>5+</sup> states. Despite the interest in P doping to improve hematite photoanodes, establishing an effective P-doping synthesis remains challenging, often resulting in suboptimal PEC outcomes. In this study, we identify that unintentional tin (Sn) diffusion from the fluorine-doped tin oxide (FTO) substrate significantly impacts P-doped Fe<sub>2</sub>O<sub>3</sub> performance. Addressing the detrimental interaction between unintentional Sn<sup>4+</sup> and intentional P<sup>5+</sup> dopants, we introduce titanium (Ti) as a guest dopant to mitigate dopant repulsion. The resulting P:Sn:Ti–Fe<sub>2</sub>O<sub>3</sub> exhibits a 4-fold increase in photocurrent density to 3.44 mA cm<sup>–2</sup> at 1.23 V<sub>RHE</sub>, marking a significant advancement in P-doped hematite research. With a NiFeO<sub><i>x</i></sub> cocatalyst, the NiFeO<sub><i>x</i></sub>/P:Sn:Ti–Fe<sub>2</sub>O<sub>3</sub> photoanode further reaches a peak photocurrent density of 4.30 mA cm<sup>–2</sup> at 1.23 V<sub>RHE</sub>. Our findings, both experimental and computational, demonstrate that overcoming negative dopant interactions is crucial for enhancing PEC performance and ensuring the photoanode’s thermodynamic stability.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448876","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 : 2024-06-25DOI: 10.1021/acscatal.4c02391
Yiying Yang, Yingyin Li, Yinghua Lu, Zhiyuan Chen, Rongchang Luo
Designing efficient heterogeneous catalysts for the atmospheric fixation of CO2 at room temperature remains a formidable challenge due to their high thermodynamic stability and kinetic inertness. Herein, a versatile nanocomposite of Aza-Por-TAPM-immobilized silver nanoparticles (AgNPs), Ag/Azo-Por-TAPM, has been successfully fabricated by adopting a three-dimensional azo-bridged porous porphyrin framework (Azo-Por-TAPM) as the porous support through a simple “liquid impregnation and in situ reduction” strategy. After adjusting the chemical structure of the porphyrin framework, the experimental results reveal that the presence of abundant azo groups and distorted tetrahedral structures is conducive to the preparation of highly dispersed and small-sized AgNPs at its surface. Further studies discover that Ag/Azo-Por-TAPM exhibits a record-level catalytic activity in the carboxylative cyclization of propargylic alcohols with CO2 at room temperature, achieving maximum turnover frequencies of 4600 h–1 at 10 bar and 1050 h–1 at 1 bar, which far exceed that of the previously reported catalysts. In addition, Ag/Aza-Por-TAPM has a high catalytic efficiency with simulated industrial fuel gas under ambient conditions and can be easily recovered and reused at least six times without a significant decrease in catalytic activity. The significantly reduced activation energy, together with the analytical results of NMR spectra, demonstrate that AgNPs-driven alkyne activation is considered as the rate-determining step of the cyclization reaction. This work not only reports a kind of porous porphyrin polymers loaded AgNPs for mild CO2 conversion but also brings some inspiration to designing highly efficient catalysts for the integration of CO2 capture and utilization.
由于异相催化剂具有较高的热力学稳定性和动力学惰性，因此设计用于常温大气固定二氧化碳的高效异相催化剂仍然是一项艰巨的挑战。本文采用三维偶氮桥接多孔卟啉框架（Azo-Por-TAPM）作为多孔支撑，通过简单的 "液体浸渍和原位还原 "策略，成功制备了偶氮-Por-TAPM-固定银纳米颗粒（AgNPs）的多功能纳米复合材料--Ag/Azo-Por-TAPM。调整卟啉框架的化学结构后，实验结果表明，丰富的偶氮基团和扭曲的四面体结构有利于在其表面制备高度分散的小尺寸 AgNPs。进一步的研究发现，Ag/Aza-Por-TAPM 在室温下催化丙炔醇与 CO2 的羧基环化反应中表现出了创纪录的催化活性，在 10 bar 和 1 bar 条件下的最大转化率分别达到了 4600 h-1 和 1050 h-1，远远超过了之前报道的催化剂。此外，在环境条件下，Ag/Aza-Por-TAPM 对模拟工业燃料气体具有很高的催化效率，并且可以轻松回收和重复使用至少六次，而不会显著降低催化活性。活化能的大幅降低以及核磁共振光谱的分析结果表明，AgNPs 驱动的炔烃活化被认为是环化反应的速率决定步骤。这项工作不仅报道了一种负载 AgNPs 的多孔卟啉聚合物用于温和的二氧化碳转化，还为设计二氧化碳捕获和利用一体化的高效催化剂带来了一些启发。
{"title":"A Three-Dimensional Azo-Bridged Porous Porphyrin Framework Supported Silver Nanoparticles as the State-of-the-Art Catalyst for the Carboxylative Cyclization of Propargylic Alcohols with CO2 under Ambient Conditions","authors":"Yiying Yang, Yingyin Li, Yinghua Lu, Zhiyuan Chen, Rongchang Luo","doi":"10.1021/acscatal.4c02391","DOIUrl":"https://doi.org/10.1021/acscatal.4c02391","url":null,"abstract":"Designing efficient heterogeneous catalysts for the atmospheric fixation of CO<sub>2</sub> at room temperature remains a formidable challenge due to their high thermodynamic stability and kinetic inertness. Herein, a versatile nanocomposite of <b>Aza-Por-TAPM</b>-immobilized silver nanoparticles (AgNPs), <b>Ag/Azo-Por-TAPM</b>, has been successfully fabricated by adopting a three-dimensional azo-bridged porous porphyrin framework (<b>Azo-Por-TAPM</b>) as the porous support through a simple “liquid impregnation and in situ reduction” strategy. After adjusting the chemical structure of the porphyrin framework, the experimental results reveal that the presence of abundant azo groups and distorted tetrahedral structures is conducive to the preparation of highly dispersed and small-sized AgNPs at its surface. Further studies discover that <b>Ag/Azo-Por-TAPM</b> exhibits a record-level catalytic activity in the carboxylative cyclization of propargylic alcohols with CO<sub>2</sub> at room temperature, achieving maximum turnover frequencies of 4600 h<sup>–1</sup> at 10 bar and 1050 h<sup>–1</sup> at 1 bar, which far exceed that of the previously reported catalysts. In addition, <b>Ag/Aza-Por-TAPM</b> has a high catalytic efficiency with simulated industrial fuel gas under ambient conditions and can be easily recovered and reused at least six times without a significant decrease in catalytic activity. The significantly reduced activation energy, together with the analytical results of NMR spectra, demonstrate that AgNPs-driven alkyne activation is considered as the rate-determining step of the cyclization reaction. This work not only reports a kind of porous porphyrin polymers loaded AgNPs for mild CO<sub>2</sub> conversion but also brings some inspiration to designing highly efficient catalysts for the integration of CO<sub>2</sub> capture and utilization.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448909","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 : 2024-06-24DOI: 10.1021/acscatal.4c02355
Marc T. Bennett, Kwanwoo A. Park, Charles B. Musgrave, III, Jack W. Brubaker, Diane A. Dickie, William A. Goddard, III, T. Brent Gunnoe
Fe(II) carboxylates react with dioxygen and carboxylic acid to form Fe6(μ–OH)2(μ3–O)2(μ–X)12(HX)2 (X = acetate or pivalate), which is an active oxidant for Rh-catalyzed arene alkenylation. Heating (150–200 °C) the catalyst precursor [(η2–C2H4)2Rh(μ–OAc)]2 with ethylene, benzene, Fe(II) carboxylate, and dioxygen yields styrene >30-fold faster than the reaction with dioxygen in the absence of the Fe(II) carboxylate additive. It is also demonstrated that Fe6(μ–OH)2(μ3–O)2(μ–X)12(HX)2 is an active oxidant under anaerobic conditions, and the reduced material can be reoxidized to Fe6(μ–OH)2(μ3–O)2(μ–X)12(HX)2 by dioxygen. At optimized conditions, a turnover frequency of ∼0.2 s–1 is achieved. Unlike analogous reactions with Cu(II) carboxylate oxidants, which undergo stoichiometric Cu(II)-mediated production of phenyl esters (e.g., phenyl acetate) as side products at temperatures ≥150 °C, no phenyl ester side product is observed when Fe carboxylate additives are used. Kinetic isotope effect experiments using C6H6 and C6D6 give kH/kD = 3.5(3), while the use of protio or monodeutero pivalic acid reveals a small KIE with kH/kD = 1.19(2). First-order dependencies on Fe(II) carboxylate and dioxygen concentration are observed in addition to complicated kinetic dependencies on the concentration of carboxylic acid and ethylene, both of which inhibit the reaction rate at a high concentration. Mechanistic studies are consistent with irreversible benzene C–H activation, ethylene insertion into the formed Rh–Ph bond, β–hydride elimination, and reaction of Rh–H with Fe6(μ–OH)2(μ3–O)2(μ–X)12(HX)2 to regenerate a Rh-carboxylate complex.
{"title":"Hexa-Fe(III) Carboxylate Complexes Facilitate Aerobic Hydrocarbon Oxidative Functionalization: Rh Catalyzed Oxidative Coupling of Benzene and Ethylene to Form Styrene","authors":"Marc T. Bennett, Kwanwoo A. Park, Charles B. Musgrave, III, Jack W. Brubaker, Diane A. Dickie, William A. Goddard, III, T. Brent Gunnoe","doi":"10.1021/acscatal.4c02355","DOIUrl":"https://doi.org/10.1021/acscatal.4c02355","url":null,"abstract":"Fe(II) carboxylates react with dioxygen and carboxylic acid to form Fe<sub>6</sub>(μ–OH)<sub>2</sub>(μ<sub>3</sub>–O)<sub>2</sub>(μ–X)<sub>12</sub>(HX)<sub>2</sub> (X = acetate or pivalate), which is an active oxidant for Rh-catalyzed arene alkenylation. Heating (150–200 °C) the catalyst precursor [(η<sup>2</sup>–C<sub>2</sub>H<sub>4</sub>)<sub>2</sub>Rh(μ–OAc)]<sub>2</sub> with ethylene, benzene, Fe(II) carboxylate, and dioxygen yields styrene >30-fold faster than the reaction with dioxygen in the absence of the Fe(II) carboxylate additive. It is also demonstrated that Fe<sub>6</sub>(μ–OH)<sub>2</sub>(μ<sub>3</sub>–O)<sub>2</sub>(μ–X)<sub>12</sub>(HX)<sub>2</sub> is an active oxidant under anaerobic conditions, and the reduced material can be reoxidized to Fe<sub>6</sub>(μ–OH)<sub>2</sub>(μ<sub>3</sub>–O)<sub>2</sub>(μ–X)<sub>12</sub>(HX)<sub>2</sub> by dioxygen. At optimized conditions, a turnover frequency of ∼0.2 s<sup>–1</sup> is achieved. Unlike analogous reactions with Cu(II) carboxylate oxidants, which undergo stoichiometric Cu(II)-mediated production of phenyl esters (e.g., phenyl acetate) as side products at temperatures ≥150 °C, no phenyl ester side product is observed when Fe carboxylate additives are used. Kinetic isotope effect experiments using C<sub>6</sub>H<sub>6</sub> and C<sub>6</sub>D<sub>6</sub> give <i>k</i><sub>H</sub>/<i>k</i><sub>D</sub> = 3.5(3), while the use of protio or monodeutero pivalic acid reveals a small KIE with <i>k</i><sub>H</sub>/<i>k</i><sub>D</sub> = 1.19(2). First-order dependencies on Fe(II) carboxylate and dioxygen concentration are observed in addition to complicated kinetic dependencies on the concentration of carboxylic acid and ethylene, both of which inhibit the reaction rate at a high concentration. Mechanistic studies are consistent with irreversible benzene C–H activation, ethylene insertion into the formed Rh–Ph bond, β–hydride elimination, and reaction of Rh–H with Fe<sub>6</sub>(μ–OH)<sub>2</sub>(μ<sub>3</sub>–O)<sub>2</sub>(μ–X)<sub>12</sub>(HX)<sub>2</sub> to regenerate a Rh-carboxylate complex.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462014","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 : 2024-06-24DOI: 10.1021/acscatal.4c01898
Karoline L. Hebisch, Risha Goel, Kinga Gołą̨bek, Pawel A. Chmielniak, Carsten Sievers
During skeletal 1-butene isomerization over ferrierite carbonaceous deposits block 98% of the micropores within 24 h, rendering them effectively inaccessible to reactants, while the catalytic activity improves continuously for 100 h on stream. Ex-situ pyridine adsorption shows that the concentration of conventional Brønsted acid sites in the 10-R channels decreases below the detection threshold of infrared spectroscopy within 2 h. However, the operando addition of the base triethyl amine to the feed quenches the reaction, showing that mediated acidity is necessary. The larger base 2,2,6,6-tetramethyl piperidine only deactivates catalytic activity after several hours because it cannot directly bind to active sites at the sterically restricted pore mouths. The communication of internal Brønsted acid sites to the external reactants via a concerted mechanism involving protonated monoaromatic deposits trapped in the pore mouths explains the promoting effects of coke species in zeolite-catalyzed skeletal butene isomerization. This work presents a consolidated explanation of the synergy of solid acidity, structural confinement, and carbonaceous deposits in zeolites.
{"title":"Synergy between Brønsted Acid Sites and Carbonaceous Deposits during Skeletal 1-Butene Isomerization over Ferrierite","authors":"Karoline L. Hebisch, Risha Goel, Kinga Gołą̨bek, Pawel A. Chmielniak, Carsten Sievers","doi":"10.1021/acscatal.4c01898","DOIUrl":"https://doi.org/10.1021/acscatal.4c01898","url":null,"abstract":"During skeletal 1-butene isomerization over ferrierite carbonaceous deposits block 98% of the micropores within 24 h, rendering them effectively inaccessible to reactants, while the catalytic activity improves continuously for 100 h on stream. <i>Ex-situ</i> pyridine adsorption shows that the concentration of conventional Brønsted acid sites in the 10-R channels decreases below the detection threshold of infrared spectroscopy within 2 h. However, the <i>operando</i> addition of the base triethyl amine to the feed quenches the reaction, showing that mediated acidity is necessary. The larger base 2,2,6,6-tetramethyl piperidine only deactivates catalytic activity after several hours because it cannot directly bind to active sites at the sterically restricted pore mouths. The communication of internal Brønsted acid sites to the external reactants <i>via</i> a concerted mechanism involving protonated monoaromatic deposits trapped in the pore mouths explains the promoting effects of coke species in zeolite-catalyzed skeletal butene isomerization. This work presents a consolidated explanation of the synergy of solid acidity, structural confinement, and carbonaceous deposits in zeolites.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448819","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 : 2024-06-24DOI: 10.1021/acscatal.4c00259
Anne-Laure Wirotius, Romain Lambert, Thomas Dardé, Simon Harrisson, Daniel Taton
N-Heterocyclic carbenes (NHCs) are among the most studied reactive species in organic chemistry. They are widely employed as ligands for transition metal catalysts and also display a rich chemistry as stoichiometric reagents and organocatalysts. Nevertheless, their sensitivity to air and moisture still limits their widespread adoption in synthesis. Taking inspiration from processive enzyme-catalyzed reactions, we have tackled this challenge by designing efficient and recyclable polymeric nanoreactors immobilizing water-compatible benzimidazolium acetate motifs in their core and showing catalytic activity akin to that of NHC units. The nanoreactors’ ability to perform micellar organocatalysis in water is established through benchmark NHC-catalyzed reactions, including benzoin condensation, transesterification, and cyanosilylation. This NHC-like micellar organocatalysis proceeds with exceptionally high activity due to a compartmentalization effect and avoids both costly purification steps and the need for solvents to isolate reaction products.
{"title":"Micellar N-Heterocyclic Carbene-like Organic Catalysis from Polymeric Nanoreactors Immobilizing Benzimidazolium Acetate Motifs in Their Core","authors":"Anne-Laure Wirotius, Romain Lambert, Thomas Dardé, Simon Harrisson, Daniel Taton","doi":"10.1021/acscatal.4c00259","DOIUrl":"https://doi.org/10.1021/acscatal.4c00259","url":null,"abstract":"N-Heterocyclic carbenes (NHCs) are among the most studied reactive species in organic chemistry. They are widely employed as ligands for transition metal catalysts and also display a rich chemistry as stoichiometric reagents and organocatalysts. Nevertheless, their sensitivity to air and moisture still limits their widespread adoption in synthesis. Taking inspiration from processive enzyme-catalyzed reactions, we have tackled this challenge by designing efficient and recyclable polymeric nanoreactors immobilizing water-compatible benzimidazolium acetate motifs in their core and showing catalytic activity akin to that of NHC units. The nanoreactors’ ability to perform micellar organocatalysis in water is established through benchmark NHC-catalyzed reactions, including benzoin condensation, transesterification, and cyanosilylation. This NHC-like micellar organocatalysis proceeds with exceptionally high activity due to a compartmentalization effect and avoids both costly purification steps and the need for solvents to isolate reaction products.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445074","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}
Anthraquinone derivatives are classes of compounds employed in the production of valuable materials. Leuco-quinizarin, the 2-electron-reduced form of quinizarin (1,4-dihydroxy-anthraquinone), is a highly active and useful reactant for the synthesis of variety of anthraquinone derivatives. However, conventional methods of leuco-quinizarin synthesis require stoichiometric amounts of inorganic reductants and acids or bases. We developed Pt/DMPSi-Al2O3 and Pt-Ni/DMPSi-Al2O3 as highly active and selective heterogeneous catalysts for the hydrogenation of quinizarins to leuco-quinizarins under neutral and continuous-flow conditions. Remarkably, bimetallic effects of Ni and Pt nanoparticle systems were highlighted in the selective hydrogenation of the substituted quinizarin. In addition, the continuous-flow synthesis of leuco-quinizarin and its derivatization reaction were integrated to be a fully continuous process using flow-batch-separator unified reactors.
{"title":"Selective Hydrogenation of Quinizarins to Leuco-quinizarins and Their Direct Derivatization Using Flow-Batch-Separator Unified Reactors under Continuous-Flow Conditions","authors":"Hiroyuki Miyamura, Aditya Sharma, Masakazu Takata, Ryosuke Kajiyama, Shu̅ Kobayashi, Yoshihiro Kon","doi":"10.1021/acscatal.4c02955","DOIUrl":"https://doi.org/10.1021/acscatal.4c02955","url":null,"abstract":"Anthraquinone derivatives are classes of compounds employed in the production of valuable materials. Leuco-quinizarin, the 2-electron-reduced form of quinizarin (1,4-dihydroxy-anthraquinone), is a highly active and useful reactant for the synthesis of variety of anthraquinone derivatives. However, conventional methods of leuco-quinizarin synthesis require stoichiometric amounts of inorganic reductants and acids or bases. We developed Pt/DMPSi-Al<sub>2</sub>O<sub>3</sub> and Pt-Ni/DMPSi-Al<sub>2</sub>O<sub>3</sub> as highly active and selective heterogeneous catalysts for the hydrogenation of quinizarins to leuco-quinizarins under neutral and continuous-flow conditions. Remarkably, bimetallic effects of Ni and Pt nanoparticle systems were highlighted in the selective hydrogenation of the substituted quinizarin. In addition, the continuous-flow synthesis of leuco-quinizarin and its derivatization reaction were integrated to be a fully continuous process using flow-batch-separator unified reactors.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":null,"pages":null},"PeriodicalIF":12.9,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448906","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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