AuAg合金纳米催化剂的制备及应用研究进展

Research Progress on the Preparation and Application of AuAg Alloy Nanocatalysts

目的纳米Au催化剂一直是多相催化领域的典型研究材料之一,其具有特殊的电子、结构性质及对诸多氧化、还原反应历程的高催化性能。但是纳米Au催化剂存在尺寸依赖性强,对O_(2)等基础物质活化能力弱等问题。Ag与Au形成合金材料则是解决上述问题的重要途径之一。已有研究中采用多种不同的AuAg催化剂制备方法,并且其在不同催化应用中涉及多种催化机理,但未有研究将其制备过程以及协同催化机理进行对比总结。因此,针对AuAg合金催化剂,综述了其常见的制备方法和预处理条件及其在CO氧化等氧化反应、不饱和醛加氢等加氢反应中的应用以及催化反应机制,并提出了未来可能的发展方向。方法通过对AuAg催化剂的研究和应用进行综述,分析了不同制备方法的特点及预处理条件对AuAg催化剂结构的影响以及AuAg催化剂在不同反应中的催化机理。结果在该合金材料的制备和预处理方面,对比了不同制备方法及其对该合金颗粒在载体表面负载状况的影响机制,也深入探讨了预处理条件对AuAg纳米粒子的尺寸及合金化程度的调控作用。在催化应用上,Ag的加入能够改善纳米Au的抗烧结能力,二者间的电子效应也可提升材料对O_(2)等基础物质活化能力,并降低Au颗粒尺寸变化对催化反应结果的影响,最终高效催化CO氧化、醇氧化、不饱和醛加氢、炔烃加氢以及硝基芳香化合物还原等反应历程。结论目前有多种制备AuAg合金纳米催化剂的方法,而其结构的可控及稳定的合成仍是未来的研究重点。同时,AuAg催化剂在不同反应中催化机理的探索对AuAg催化剂的定向设计尤为重要,应进行更深入的研究,以更快实现工业应用。

Objective Nano Au catalyst has been studied extensively in heterogeneous catalysis due to its unique electronic and structure properties,as well as high catalytic performance in various oxidation and reduction reactions.However,nano Au catalysts exhibit strong sensitivity to particle size and weak activation ability towards basic substances like O_2.The formation of alloy materials with Ag and Au is one of the effective ways to solve the above problems.Various preparation methods for AuAg catalysts have been studied.The catalytic mechanism for different reactions has been explored extensively.However,there is no research giving a summary to compare different preparation methods of AuAg catalysts and mechanisms of varied reactions.For this reason,this study reviewed the common preparation methods and pretreatment conditions of AuAg alloy catalysts,as well as their applications and catalytic reaction mechanisms in oxidation reactions such as CO oxidation and hydrogenation reactions such as unsaturated aldehyde hydrogenation.Moreover,future possible directions for development were proposed.Methods By reviewing the research and application of AuAg catalysts,the characteristics of different preparation methods and the influence of pretreatment conditions on the structure of AuAg catalysts,as well as the catalytic mechanisms of AuAg catalysts in different reactions,were analyzed.Results In terms of the preparation and pretreatment of this alloy material,different preparation methods and their influence mechanisms on the loading status of this alloy particles on the carrier surface were compared.The role of pretreatment conditions in regulating the size and alloying degree of AuAg nanoparticles was also thoroughly explored.In terms of catalytic applications,the addition of Ag improved the sintering resistance of nano Au.Moreover,the electronic interaction between Au and Ag enhanced the activity towards typical chemicals such as O_(2)and significantly reduced the size-dependency of the reaction result catalyzed by a single Au material.Thus,the synergy of AuAg alloy results in high catalytic efficiency towards various reaction processes,such as CO oxidation,alcohol oxidation,unsaturated aldehyde hydrogenation,alkyne hydrogenation,and nitroaromatic compound reduction.Conclusion Currently,there are many methods for preparing AuAg alloy nano-catalysts,and the controllable and stable synthesis methods of AuAg catalysts are still the focus of future research.Meanwhile,the exploration of catalytic mechanisms of AuAg catalysts in different reactions is particularly important for the directional design of AuAg catalysts,and further in-depth research should be conducted to accelerate industrial applications of AuAg catalysts.