Conversion of CO₂ to CO via hydrogenation, also known as the reverse water-gas shift (RWGS) reaction, is an important chemical process to generate CO as a platform chemical for further conversions. Metallic Cu catalyzes the RWGS reaction at a temperature of 500 ^oC with a high initial turnover frequency, but surface structural reorganization and particle growth at the reaction temperature deleteriously reduce its activities over time. In this work, we synthesized hierarchical structures of porous Cu@C and Cu/Zn@C materials via pyrolysis of Cu-BTC Metal-Organic Frameworks (MOFs) with or without Zn doping. Carbon encapsulation protects the Cu NPs from sintering, leading to stable catalytic activity at 500 ^oC under which RWGS is favored. Furthermore, the final catalyst pellet size can be controlled by tuning the crystal size of MOF precursors, eliminating the step of forming catalysts for fixed bed reactor applications.

中文翻译：

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金属-有机骨架热解为多层多孔Cu / Zn-纳米颗粒@碳材料，以实现高效的CO ₂加氢

通过氢化将CO ₂转化为CO的过程，也称为反向水煤气变换（RWGS）反应，是重要的化学过程，可将CO生成为进一步转化的平台化学品。金属铜在500 ^o C的温度下以较高的初始周转频率催化RWGS反应，但是随着时间的推移，表面结构的重组和颗粒在反应温度下的生长有害地降低了其活性。在这项工作中，我们通过具有或不具有锌掺杂的Cu-BTC金属有机骨架（MOF）的热解，合成了多孔Cu @ C和Cu / Zn @ C材料的分层结构。碳封装可保护铜纳米颗粒免于烧结，从而在500 ^{o C时}具有稳定的催化活性C，RWGS受到青睐。此外，可以通过调节MOF前体的晶体尺寸来控制最终催化剂颗粒的尺寸，省去了形成用于固定床反应器应用的催化剂的步骤。