Au/Co_(3)O_(4)-ZnO催化剂上CO_(2)-丙三醇羰基化合成丙三醇碳酸酯

Photothermal Synthesis of Glycerol Carbonate via Glycerol Carbonylation with CO_(2) over Au/Co_(3)O_(4)-ZnO Catalyst

CO_(2)与丙三醇羰基化合成丙三醇碳酸酯是一项前景广阔的CO_(2)利用途径。尽管该反应可以通过热驱动的催化途径实现,但受热力学平衡的限制。在本研究中,我们开发了xAu/20Co_(3)O_(4)-ZnO系列催化剂,并引入太阳光辐射能量来实现光热协同催化反应,以突破热力学限制。由p型半导体Co_(3)O_(4)和n型半导体ZnO复合而成的Co_(3)O_(4)-ZnO氧化物具有异质结构,而负载于Co_(3)O_(4)-ZnO表面的Au纳米粒子具有局域表面等离子体共振(LSPR)效应。我们研究了xAu/20Co_(3)O_(4)-ZnO的可见光吸收性能、光生电子-空穴对分离效率以及Au添加对xAu/20Co_(3)O_(4)-ZnO催化剂光热协同催化性能的影响。此外,我们还研究了Au掺杂对xAu/20Co_(3)O_(4)-ZnO的体相和表面性质(晶相结构、形貌、比表面积、元素结合能、表面酸碱性、还原行为)的影响。研究结果显示,Au/20Co_(3)O_(4)-ZnO的异质结构有助于吸收可见光并提高电子-空穴对的分离效率。负载于Co_(3)O_(4)-ZnO表面的Au纳米颗粒约为50 nm,Au的加入改变了Zn和Co的电子密度,增强了Co物种的还原性,并增加了Co_(3)O_(4)-ZnO表面的氧空位。此外,Au纳米粒子的LSPR进一步提高了Au/20Co_(3)O_(4)-ZnO的可见光吸收能力,并改善了光生电子-空穴对的分离,从而提高了光热协同催化性能。在优化的条件下(150℃、5 MPa、6 h、25 W可见光照射),2%Au/20Co_(3)O_(4)-ZnO表现出良好的光热协同催化性能,丙三醇碳酸酯的产率为6.5%。这项工作有望为合理设计更好的CO_(2)-丙三醇羰基化制丙三醇碳酸酯光热催化剂提供参考。

Glycerol carbonylation with CO_(2) to synthesize glycerol carbonate is a promising approach for CO_(2) utilization.This reaction can be achieved through a thermally-driven catalytic pathway,but it is constrained by thermodynamic equilibrium.In the present study,we introduced solar energy into the reaction system to enable a photo-thermal synergistic catalytic reaction,breaking through the thermodynamic limitations.We developed a series of xAu/20Co_(3)O_(4)-ZnO catalysts,where Co_(3)O_(4)-ZnO,a composite of p-type semiconductor Co_(3)O_(4) and n-type semi-conductor ZnO,exhibited a heterojunction structure,and Au nanoparticles loaded onto the surface of Co_(3)O_(4)-ZnO revealed the localized surface plasmon resonance(LSPR).We investigated the ability of xAu/Co_(3)O_(4)-ZnO to absorb visible light absorption,the efficiency of separating photo-generated hole-electron pairs,and the impact of Au on the photothermal synergistic catalytic performances of Au/Co_(3)O_(4)-ZnO catalysts.We also examined the effects of Au doping on the bulk and surface properties,including crystalline structures,morphologies,specific surface areas and pore structures,the binding energies of the elements,surface acid-base sites,and reduction behaviors of xAu/Co_(3)O_(4)-ZnO.Our findings revealed that the heterojunction structure of Au/20Co_(3)O_(4)-ZnO facilitated visible light absorption and hole-electron pair separation.The size of Au nano-particles(NPs)loaded on Co_(3)O_(4)-ZnO surface was approximately 50 nm.The loading of Au altered the electron density of Co and Zn,improved the reducibility of Co species,and enhanced the presence of oxygen vacancies on Co_(3)O_(4)-ZnO surface.The LSPR of Au NPs further enhanced the visible light absorption capacity of Au/20Co_(3)O_(4)-ZnO,and improved the separating of photogenerated hole-electron pairs,thus enhancing the photothermal catalytic performances.With the optimizing conditions(150℃,5 MPa,6 h,and 225 W visible light irradiation),the 2%Au/20Co_(3)O_(4)-ZnO catalyst demonstrated excellent performances,yielding a glycerol carbonate yield of 6.5%.This study is expected to serve as a reference for the rational design of improved photothermal catalysts for glycerol carbonylation with CO_(2) to produce glycerol carbonate in the future.