Chinese Journal of Catalysis最新文献

Dual-channel redox reactions for photocatalytic H2-evolution coupled with photoreforming oxidation of waste materials 双通道氧化还原反应，用于光催化 H2 进化和废料的光转化氧化

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60118-X

Dual-channel redox reaction system is advantageous for photocatalytic hydrogen (H₂) production when coupled with photoreforming oxidation of waste materials, benefiting both thermodynamically and kinetically. However, existing reviews primarily focus on specific oxidation reactions, such as oxidative organic synthesis and water remediation, often neglecting recent advancements in plastic upgrading, biomass conversion, and H₂O₂ production, and failing to provide an in-depth discussion of catalytic mechanisms. This review addresses these gaps by offering a comprehensive overview of recent advancements in dual-channel redox reactions for photocatalytic H₂-evolution and waste photoreforming. It highlights waste-to-wealth design concepts, examines the challenges, advantages and diverse applications of dual-channel photocatalytic reactions, including photoreforming of biomass, alcohol, amine, plastic waste, organic pollutants, and H₂O₂ production. Emphasizing improvement strategies and exploration of catalytic mechanisms, it includes advanced in-situ characterization, spin capture experiments, and DFT calculations. By identifying challenges and future directions in this field, this review provides valuable insights for designing innovative dual-channel photocatalytic systems.

双通道氧化还原反应系统在光催化制氢（H2）过程中与废料的光形成氧化反应相结合，在热力学和动力学方面都具有优势。然而，现有的综述主要关注特定的氧化反应，如氧化有机合成和水修复，往往忽视了塑料升级、生物质转化和 H2O2 生产方面的最新进展，也没有对催化机理进行深入讨论。本综述针对这些不足，全面概述了用于光催化 H2 进化和废物光转化的双通道氧化还原反应的最新进展。文章重点介绍了变废为宝的设计理念，探讨了双通道光催化反应的挑战、优势和各种应用，包括生物质、酒精、胺、塑料废物、有机污染物的光转化和 H2O2 生产。该书强调改进策略和催化机理探索，包括先进的原位表征、自旋捕获实验和 DFT 计算。通过确定该领域的挑战和未来方向，本综述为设计创新的双通道光催化系统提供了宝贵的见解。

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引用次数: 0

Mg-doped SrTaO2N as a visible-light-driven H2-evolution photocatalyst for accelerated Z-scheme overall water splitting 掺镁 SrTaO2N 作为可见光驱动的 H2 演变光催化剂，用于加速 Z 型整体水分离

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60082-3

Perovskite SrTaO₂N is one of the most promising narrow-bandgap photocatalysts for Z-scheme overall water splitting. However, the formation of defect states during thermal nitridation severely hinders the separation of charges, resulting in poor photocatalytic activity. In the present study, we successfully synthesize SrTaO₂N photocatalyst with low density of defect states, uniform morphology and particle size by flux-assisted one-pot nitridation combined with Mg doping. Some important parameters, such as the size of unit cell, the content of nitrogen, and microstructure, prove the successful doping of Mg. The defect-related carrier recombination has been significantly reduced by Mg doping, which effectively promotes the charge separation. Moreover, Mg doping induces a change of the band edge, which makes proton reduction have a stronger driving force. After modifying with the core/shell-structured Pt/Cr₂O₃ cocatalyst, the H₂ evolution activity of the optimized SrTaO₂N:Mg is 10 times that of the undoped SrTaO₂N, with an impressive apparent quantum yield of 1.51% at 420 nm. By coupling with Au-FeCoO_x modified BiVO₄ as an O₂-evolution photocatalyst and [Fe(CN)₆]³⁻/[Fe(CN)₆]⁴⁻ as the redox couple, a redox-based Z-scheme overall water splitting system is successfully constructed with an apparent quantum yield of 1.36% at 420 nm. This work provides an alternative way to prepare oxynitride semiconductors with reduced defects to promote the conversion of solar energy.

透辉石 SrTaO2N 是最有前途的 Z 型整体水分离窄带隙光催化剂之一。然而，热氮化过程中缺陷态的形成严重阻碍了电荷的分离，导致光催化活性较差。在本研究中，我们通过通量辅助一锅氮化结合掺杂镁，成功合成了缺陷态密度低、形貌和粒度均匀的 SrTaO2N 光催化剂。单胞尺寸、氮含量和微观结构等一些重要参数证明了掺镁的成功。掺入镁后，与缺陷有关的载流子重组显著减少，从而有效地促进了电荷分离。此外，掺杂镁还会引起带边的变化，从而使质子还原具有更强的驱动力。在与核/壳结构的 Pt/Cr2O3 催化剂修饰后，优化的 SrTaO2N:Mg 的 H2 演化活性是未掺杂 SrTaO2N 的 10 倍，在 420 纳米波长下的表观量子产率高达 1.51%。以 Au-FeCoOx 修饰的 BiVO4 作为 O2 演化光催化剂，以[Fe(CN)6]3-/[Fe(CN)6]4- 作为氧化还原偶联剂，成功构建了基于氧化还原的 Z 型整体水分离体系，420 纳米波长下的表观量子产率为 1.36%。这项工作为制备缺陷减少的氮氧化物半导体以促进太阳能转换提供了另一种途径。

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引用次数: 0

Activating d10 electronic configuration to regulate p-band centers as efficient active sites for solar energy conversion into H2 by surface atomic arrangement 激活 d10 电子构型，通过表面原子排列调节 p 波段中心，使其成为将太阳能转化为 H2 的高效活性位点

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60119-1

Relationship between the activity for photocatalytic H₂O overall splitting (HOS) and the electron occupancy on d orbits of the active component in photocatalysts shows volcanic diagram, and specially the d¹⁰ electronic configuration in valley bottom exhibits inert activity, which seriously fetters the development of catalytic materials with great potentials. Herein, In d¹⁰ electronic configuration of In₂O₃ was activated by phosphorus atoms replacing its lattice oxygen to regulate the collocation of the ascended In 5p-band (In ɛ_5p) and descended O 2p-band (O ɛ_2p) centers as efficient active sites for chemisorption to *OH and *H during forward HOS, respectively, along with a declined In 4d-band center (In ɛ_4d) to inhibit its backward reaction. A stable STH efficiency of 2.23% under AM 1.5 G irradiation at 65 °C has been obtained over the activated d¹⁰ electronic configuration with a lowered activation energy for H₂ evolution, verified by femtosecond transient absorption spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations of dynamics. These findings devote to activating d¹⁰ electronic configuration for resolving the reaction energy barrier and dynamical bottleneck of forward HOS, which expands the exploration of high-efficiency catalytic materials.

光催化H2O整体裂解（HOS）活性与光催化剂中活性组分d轨道上电子占位的关系呈现火山图，特别是谷底的d10电子构型表现出惰性活性，严重阻碍了具有巨大潜力的催化材料的发展。在此，通过磷原子取代In2O3晶格中的氧，激活了In2O3的d10电子构型，从而调节了上升的In 5p带（In ɛ5p）和下降的O 2p带（O ɛ2p）中心的配位，使其分别成为正向HOS过程中*OH和*H化学吸附的有效活性位点，同时，下降的In 4d带中心（In ɛ4d）抑制了其逆反应。飞秒瞬态吸收光谱、原位漫反射红外傅立叶变换光谱和动力学理论计算证实，在 65 °C、AM 1.5 G 辐照条件下，活化的 d10 电子构型的稳定 STH 效率为 2.23%，H2 演化的活化能降低。这些发现有助于激活 d10 电子构型，从而解决正向氢氧化钠的反应能量障碍和动力学瓶颈，拓展了高效催化材料的研究领域。

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引用次数: 0

Highly selective electrosynthesis of imines via electroreduction coupling of nitroarenes with aryl aldehydes on Co9S8 with positively charged sulfur vacancies 在带正电荷硫空位的 Co9S8 上通过硝基烯烃与芳基醛的电还原偶联高选择性地电合成亚胺

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60115-4

The electrocatalytic synthesis of imines through the reductive imination of nitroarenes with aldehydes is a facile, environmentally friendly, and valuable process. In this study, high selectivity electrosynthesis of imines was realized through the electrocatalytic C-N coupling reaction between nitroarenes and aryl aldehydes on Co₉S₈ nanoflowers with rich sulfur vacancies (Co₉S₈-V_s). Comparative experiments revealed that positively charged sulfur vacancies play a pivotal role in boosting catalytic selectivity towards imines. Electron-deficient sulfur vacancies intensified the adsorption of negatively charged Ph-NO₂, thereby enhancing the conversion rate of the electrochemical nitrobenzene-reduction reaction (eNB-RR). Simultaneously, sulfur vacancies augmented the adsorption capability of negatively charged Ph-CHO, enriching Ph-CHO species at the electrode interface and expediting the Schiff base condensation reaction rate. The experimental results show that the reaction conditions can satisfy the different nitroarenes and aryl aldehydes in the electrocatalytic aqueous-phase system under mild conditions to obtain the corresponding imine products in high selectivity. This study provides a facile and environmentally friendly pathway for future electrocatalytic synthesis of imine.

通过硝基烯烃与醛的还原亚胺化反应电催化合成亚胺是一种简便、环保和有价值的工艺。本研究通过在富含硫空位的 Co9S8 纳米流体（Co9S8-Vs）上进行硝基烯烃与芳基醛的电催化 C-N 偶联反应，实现了亚胺的高选择性电合成。对比实验表明，带正电荷的硫空位在提高对亚胺的催化选择性方面起着关键作用。缺电子的硫空位增强了对带负电的 Ph-NO2 的吸附，从而提高了电化学硝基苯还原反应（eNB-RR）的转化率。同时，硫空位增强了带负电荷的 Ph-CHO 的吸附能力，使 Ph-CHO 物种在电极界面富集，加快了希夫碱缩合反应的速率。实验结果表明，在电催化水相体系中，反应条件可以满足不同硝基烯烃和芳基醛在温和条件下以高选择性得到相应的亚胺产物。这项研究为今后电催化合成亚胺提供了一条简便、环保的途径。

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引用次数: 0

Unraveling the roles of atomically-dispersed Au in boosting photocatalytic CO2 reduction and aryl alcohol oxidation 揭示原子分散金在促进光催化二氧化碳还原和芳基醇氧化中的作用

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60109-9

Atomically-dispersed metal-based materials represent an emerging class of photocatalysts attributed to their high catalytic activity, abundant surface active sites, and efficient charge separation. Nevertheless, the roles of different forms of atomically-dispersed metals (i.e., single-atoms and atomic clusters) in photocatalytic reactions remain ambiguous. Herein, we developed an ethylenediamine (EDA)-assisted reduction method to controllably synthesize atomically dispersed Au in the forms of Au single atoms (Au_SA), Au clusters (Au_C), and a mixed-phase of Au_SA and Au_C (Au_SA+C) on CdS. In addition, we elucidate the synergistic effect of Au_SA and Au_C in enhancing the photocatalytic performance of CdS substrates for simultaneous CO₂ reduction and aryl alcohol oxidation. Specifically, Au_SA can effectively lower the energy barrier for the CO₂→*COOH conversion, while Au_C can enhance the adsorption of alcohols and reduce the energy barrier for dehydrogenation. As a result, the Au_SA and Au_C co-loaded CdS show impressive overall photocatalytic CO₂ conversion performance, achieving remarkable CO and BAD production rates of 4.43 and 4.71 mmol g⁻¹ h⁻¹, with the selectivities of 93% and 99%, respectively. More importantly, the solar-to-chemical conversion efficiency of Au_SA+C/CdS reaches 0.57%, which is over fivefold higher than the typical solar-to-biomass conversion efficiency found in nature (ca. 0.1%). This study comprehensively describes the roles of different forms of atomically-dispersed metals and their synergistic effects in photocatalytic reactions, which is anticipated to pave a new avenue in energy and environmental applications.

原子分散金属材料具有催化活性高、表面活性位点丰富、电荷分离效率高等特点，是一类新兴的光催化剂。然而，不同形式的原子分散金属（即单原子和原子团簇）在光催化反应中的作用仍不明确。在此，我们开发了一种乙二胺（EDA）辅助还原法，在 CdS 上可控地合成了原子分散金，其形式包括金单质（AuSA）、金团簇（AuC）以及 AuSA 和 AuC 的混合相（AuSA+C）。此外，我们还阐明了 AuSA 和 AuC 在提高 CdS 底物同时进行二氧化碳还原和芳基醇氧化的光催化性能方面的协同效应。具体来说，AuSA 可有效降低 CO2→*COOH 转化的能障，而 AuC 可增强对醇的吸附并降低脱氢的能障。因此，AuSA 和 AuC 共同负载的 CdS 显示出令人印象深刻的整体光催化 CO2 转化性能，显著的 CO 和 BAD 生成率分别达到 4.43 和 4.71 mmol g-1 h-1，选择性分别为 93% 和 99%。更重要的是，AuSA+C/CdS 的太阳能-化学转化效率达到 0.57%，比自然界中典型的太阳能-生物质转化效率（约 0.1%）高出五倍以上。这项研究全面描述了不同形式的原子分散金属在光催化反应中的作用及其协同效应，有望为能源和环境应用开辟一条新途径。

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引用次数: 0

Ab initio molecular dynamics simulation reveals the influence of entropy effect on Co@BEA zeolite-catalyzed dehydrogenation of ethane Ab initio 分子动力学模拟揭示了熵效应对 Co@BEA 沸石催化乙烷脱氢反应的影响

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60116-6

The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate. To understand the impact of entropy, we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures. AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased. Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction. The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels. We provided explanations consistent with the principles of thermodynamics and statistical physics. The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.

烷烃脱氢反应中的 C-H 键活化是决定反应速率的关键步骤。为了解熵的影响，我们在不同温度下对 Co@BEA 沸石上的乙烷脱氢反应进行了ab initio 静态和分子动力学自由能模拟。AIMD 模拟显示，随着温度的升高，自由能垒急剧下降。我们对活化自由能的温度依赖性进行了分析，发现了伴随反应发生的不寻常的熵效应。在不同温度下，Co 活性位点周围独特的空间结构既影响了过渡态中电荷转移的程度，也影响了 3d 轨道能级的排列。我们提供了符合热力学和统计物理学原理的解释。在原子水平上获得的见解为局部化学反应和广泛化学环境之间错综复杂的长程相互作用提供了全新的解释。

引用次数: 0

Understanding the roles of Brønsted/Lewis acid sites on manganese oxide-zeolite hybrid catalysts for low-temperature NH3-SCR 了解用于低温 NH3-SCR 的氧化锰-沸石杂化催化剂上的布氏/路易斯酸位点的作用

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60112-9

Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_x removal reactions through the inter-particle diffusion of intermediate species, their subsequent reaction mechanism on acid sites is still unclear and requires investigation. In this study, the distribution of Brønsted/Lewis acid sites in the hybrid materials was precisely adjusted by introducing potassium ions, which not only selectively bind to Brønsted acid sites but also potentially affect the formation and diffusion of activated NO species. Systematic in situ diffuse reflectance infrared Fourier transform spectroscopy analyses coupled with selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) reaction demonstrate that the Lewis acid sites over MnO_x are more active for NO reduction but have lower selectivity to N₂ than Brønsted acids sites. Brønsted acid sites primarily produce N₂, whereas Lewis acid sites primarily produce N₂O, contributing to unfavorable N₂ selectivity. The Brønsted acid sites present in Y zeolite, which are stronger than those on MnO_x, accelerate the NH₃-SCR reaction in which the nitrite/nitrate species diffused from the MnO_x particles rapidly convert into the N₂. Therefore, it is important to design the catalyst so that the activated NO species formed in MnO_x diffuse to and are selectively decomposed on the Brønsted acid sites of H-Y zeolite rather than that of MnO_x particle. For the physically mixed H-MnO_x+H-Y sample, the abundant Brønsted/Lewis acid sites in H-MnO_x give rise to significant consumption of activated NO species before their inter-particle diffusion, thereby hindering the enhancement of the synergistic effects. Furthermore, we found that the intercalated K⁺ in K-MnO_x has an unexpected favorable role in the NO reduction rate, probably owing to faster diffusion of the activated NO species on K-MnO_x than H-MnO_x. This study will help to design promising metal oxide-zeolite hybrid catalysts by identifying the role of the acid sites in two different constituents.

尽管人们早已知道金属氧化物-沸石杂化材料可以通过中间产物的颗粒间扩散来提高氮氧化物去除反应的催化活性和选择性，但其在酸性位点上的后续反应机制仍不清楚，需要进行研究。在本研究中，通过引入钾离子精确调整了杂化材料中的布氏/刘易斯酸位点分布，钾离子不仅能选择性地与布氏酸位点结合，还可能影响活化 NO 物种的形成和扩散。系统的原位漫反射红外傅立叶变换光谱分析以及选择性催化还原氮氧化物与 NH3（NH3-SCR）反应表明，MnOx 上的路易斯酸位点对还原氮氧化物的活性更高，但对 N2 的选择性低于布氏酸位点。布氏酸性位点主要产生 N2，而路易斯酸性位点主要产生 N2O，从而导致对 N2 的选择性降低。Y 沸石中的布氏硬度酸比 MnOx 上的布氏硬度酸更强，从而加速了 NH3-SCR 反应，在该反应中，从 MnOx 颗粒扩散的亚硝酸盐/硝酸盐迅速转化为 N2。因此，重要的是设计催化剂，使 MnOx 中形成的活化 NO 物种扩散到 H-Y 沸石的布氏酸位点而不是 MnOx 颗粒的布氏酸位点，并在这些位点上选择性地分解。对于物理混合的 H-MnOx+H-Y 样品，H-MnOx 中丰富的布氏/路易斯酸位点会在活化的 NO 物种在颗粒间扩散之前大量消耗，从而阻碍协同效应的增强。此外，我们还发现，K-MnOx 中的插层 K+ 在氮氧化物还原速率中起到了意想不到的有利作用，这可能是由于活化的氮氧化物物种在 K-MnOx 上的扩散速度快于 H-MnOx。这项研究通过确定两种不同成分中酸性位点的作用，有助于设计出有前途的金属氧化物-沸石杂化催化剂。

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引用次数: 0

Promoting role of Ru species on Ir-Fe/BN catalyst in 1,2-diols hydrogenolysis to secondary alcohols Ir-Fe/BN 催化剂上的 Ru 物种在 1,2-二醇氢解为仲醇过程中的促进作用

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60110-5

Noble metal-based-bimetallic catalysts have been highly investigated and applied in wide applications including biomass transformation via regioselective C−O hydrogenolysis while further modification especially with noble metal is highly promising yet still under investigation. Herein, Ru was found as an effective modifier among the screened noble metals (Ru, Pt, Rh, Pd, Au, and Ag) for Ir-Fe/BN (Ir = 5 wt%, Fe/Ir = 0.25) catalyst in terminal C−O hydrogenolysis of 1,2-butanediol (1,2-BuD) to 2-butanol (2-BuOH). Only trace amount of Ru (up to 0.5 wt%) was effective in terms of high 2-BuOH selectivity (> 60%) and activity (about twice). Larger amount of Ru species (3 wt%) highly enhanced the activity but gave low selectivity to 2-BuOH with by-products of terminal C−C bond scission. Optimized catalyst (Ru(0.5)-Ir-Fe/BN) was reusable at least 4 times and gave moderate 2-BuOH yield (47%) in hydrogenolysis of 1,2-BuD. The promoting effect of Ru addition (0.5 wt%) to Ir-Fe/BN on hydrogenolysis of various alcohols was also confirmed. Combining catalytic tests with various characterizations, the promotion mechanism of Ru species in trimetallic catalysts was clarified. The Ru species in Ru(0.5)-Ir-Fe/BN form alloy with Ir and are enriched at the interface with BN surface, and direct interaction between Ru and Fe was not necessary in Ru-Ir-Fe alloy. The interface of Ir and Fe on the surface of Ir-Fe alloy may work as active sites for 1,2-diols to secondary alcohols via direct C−O hydrogenolysis, in which Ru-modified Ir activates H₂ to form hydride-like species. The activity of Ru species in C−C bond cleavage was highly suppressed due to the direct interaction with Ir species and less exposed to substrate. Larger loading amount of Ru species (3 wt%) led to the formation Ru-rich trimetallic alloy, which further works as active sites for C−C bond scission.

贵金属基双金属催化剂已经得到了广泛的研究和应用，包括通过区域选择性 C-O 加氢分解进行生物质转化。本文发现，在 1,2-丁二醇（1,2-BuD）转化为 2-丁醇（2-BuOH）的末端 C-O 氢解过程中，在经过筛选的贵金属（Ru、Pt、Rh、Pd、Au 和 Ag）中，Ru 是 Ir-Fe/BN（Ir = 5 wt%，Fe/Ir = 0.25）催化剂的有效改性剂。只有微量的 Ru（最多 0.5 wt%）才能有效地提高 2-BuOH 的选择性（60%）和活性（约两倍）。较大量的 Ru（3 wt%）可显著提高活性，但对 2-BuOH 的选择性较低，且存在末端 C-C 键断裂的副产物。优化后的催化剂（Ru(0.5)-Ir-Fe/BN）可重复使用至少 4 次，在 1,2-BuD 的氢解过程中，2-BuOH 的产率适中（47%）。在 Ir-Fe/BN 中添加 Ru（0.5 wt%）对各种醇的氢解的促进作用也得到了证实。结合催化测试和各种表征，阐明了三金属催化剂中 Ru 物种的促进机理。Ru(0.5)-Ir-Fe/BN 中的 Ru 物种与 Ir 形成合金，并在与 BN 表面的界面处富集，Ru-Ir-Fe 合金中 Ru 与 Fe 之间不需要直接作用。Ir-Fe 合金表面的 Ir 和 Fe 界面可能是 1,2-二醇通过直接 C-O 氢解转化为仲醇的活性位点，其中 Ru 改性 Ir 能激活 H2 形成类似氢化物的物种。由于 Ru 物种与 Ir 物种直接相互作用，与底物的接触较少，C-C 键裂解中 Ru 物种的活性被高度抑制。较大的 Ru 物种负载量（3 wt%）导致形成富含 Ru 的三金属合金，从而进一步成为 C-C 键裂解的活性位点。

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引用次数: 0

CO2-assisted oxidation dehydrogenation of light alkanes over metal-based heterogeneous catalysts 在金属基异质催化剂上进行 CO2- 辅助轻烷氧化脱氢反应

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60094-X

Light olefins are important platform feedstocks in the petrochemical industry, and the ongoing global economic development has driven sustained growth in demand for these compounds. The dehydrogenation of alkanes, derived from shale gas, serves as an alternative olefins production route. Concurrently, the target of realizing carbon neutrality promotes the comprehensive utilization of greenhouse gas. The integrated process of light alkanes dehydrogenation and carbon dioxide reduction (CO₂-ODH) can produce light olefins and realize resource utilization of CO₂, which has gained wide popularity. With the introduction of CO₂, coke deposition and metal reduction encountered in alkanes dehydrogenation reactions can be effectively suppressed. CO₂-assisted alkanes dehydrogenation can also reduce the risk of potential explosion hazard associated with O₂-oxidative dehydrogenation reactions. Recent investigations into various metal-based catalysts including mono- and bi-metallic alloys and oxides have displayed promising performances due to their unique properties. This paper provides the comprehensive review and critical analysis of advancements in the CO₂-assisted oxidative dehydrogenation of light alkanes (C2-C4) on metal-based catalysts developed in recent years. Moreover, it offers a comparative summary of the structural properties, catalytic activities, and reaction mechanisms over various active sites, providing valuable insights for the future design of dehydrogenation catalysts.

轻烯烃是石化工业的重要平台原料，全球经济的持续发展推动了对这些化合物需求的持续增长。从页岩气中提取的烷烃脱氢可作为烯烃的替代生产路线。同时，实现碳中和的目标也促进了温室气体的综合利用。轻质烷烃脱氢和二氧化碳还原（CO2-ODH）一体化工艺既能生产轻质烯烃，又能实现二氧化碳的资源化利用，受到广泛欢迎。引入二氧化碳后，可有效抑制烷烃脱氢反应中遇到的焦炭沉积和金属还原。二氧化碳辅助的烷烃脱氢反应还可以降低与 O2 氧化脱氢反应相关的潜在爆炸危险。近期对各种金属基催化剂（包括单、双金属合金和氧化物）的研究显示，这些催化剂因其独特的性能而具有良好的表现。本文对近年来开发的金属基催化剂在 CO2-辅助轻烷（C2-C4）氧化脱氢反应中取得的进展进行了全面综述和批判性分析。此外，本文还对各种活性位点的结构特性、催化活性和反应机理进行了比较总结，为未来脱氢催化剂的设计提供了宝贵的见解。

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引用次数: 0

Mechanism study on the influence of surface properties on the synthesis of dimethyl carbonate from CO2 and methanol over ceria catalysts 表面性质对铈催化剂以二氧化碳和甲醇为原料合成碳酸二甲酯的影响机理研究

IF 15.7 1区化学 Q1 CHEMISTRY, APPLIED

Chinese Journal of Catalysis

Pub Date : 2024-10-01 DOI: 10.1016/S1872-2067(24)60091-4

The direct synthesis of dimethyl carbonate (DMC) from CO₂ and methanol has attracted much attention as an environmentally benign and alternative route for conventional routes. Herein, a series of cerium oxide catalysts with various textural features and surface properties were prepared by the one-pot synthesis method for the direct DMC synthesis from CO₂ and methanol, and the structure-performance relationship was investigated in detail. Characterization results revealed that both of surface acid-base properties and the oxygen vacancies contents decreased with the rising crystallinity at increasingly higher calcination temperature accompanied by an unexpectedly volcano-shaped trend of DMC yield observed on the catalysts. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies indicated that the adsorption rate of methanol is slower than that of CO₂ and the methanol activation state largely influences the formation of key intermediate. Although the enhanced surface acidity-basicity and oxygen vacancies brought by low-temperature calcination could facilitate the activation of CO₂, the presence of excess strongly basic sites on low-crystallinity sample was detrimental to DMC synthesis due to the preferred formation of unreactive mono/polydentate carbonates as well as the further impediment of methanol activation. Moreover, with the use of 2-cyanopyridine as a dehydration reagent, the DMC synthesis was found to be both influenced by the promotion from the rapid in situ removal of water and the inhibition from the competitive adsorption of hydration products on the same active sites.

以二氧化碳和甲醇为原料直接合成碳酸二甲酯（DMC）作为一种对环境无害且可替代传统工艺的方法备受关注。本文采用一锅合成法制备了一系列具有不同质构特征和表面性质的氧化铈催化剂，用于以二氧化碳和甲醇为原料直接合成碳酸二甲酯（DMC），并详细研究了其结构-性能关系。表征结果表明，随着煅烧温度的升高，表面酸碱性质和氧空位含量都随着结晶度的升高而降低，同时催化剂上的 DMC 产率出现了意想不到的火山状变化趋势。原位漫反射红外傅立叶变换光谱（DRIFTS）研究表明，甲醇的吸附速率比 CO2 慢，甲醇的活化状态在很大程度上影响了关键中间产物的形成。虽然低温煅烧带来的表面酸碱性和氧空位的增强有利于 CO2 的活化，但低结晶度样品上过量强碱性位点的存在不利于 DMC 的合成，因为这些位点会优先形成无反应的单/多齿碳酸盐，并进一步阻碍甲醇的活化。此外，在使用 2-氰基吡啶作为脱水试剂时，发现 DMC 的合成既受到快速原位脱水的促进作用的影响，也受到水合产物竞争性吸附在同一活性位点上的抑制作用的影响。

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引用次数: 0