Dai Xinyan, Sun Yugang
Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, USA.
Nanoscale Horiz. 2024 Mar 25;9(4):627-636. doi: 10.1039/d3nh00506b.
Selective hydrogenation of CO to yield CH relies on the appropriate catalysts that can facilitate the cleavage of CO bonds and dissociative adsorption of H. Ultrafine Rh nanoparticles loaded on silica nanospheres were used as a class of photocatalysts to significantly improve the selectivity and reaction rate of producing CH from the mixture of CO and H under the illumination of a broadband visible light source. The intense light scattering resonances in the silica nanospheres generate strong electric fields near the silica surface to enhance the light absorption power in the supported ultrafine Rh nanoparticles, promoting the efficiency of hot electron generation in the Rh nanoparticles. The interaction of the hot electrons with the adsorbate species on the Rh nanoparticle surface weakens the C-O bond to facilitate the deoxygenation of CO, favoring the production of CH with a unity selectivity at a faster rate in the presence of surface adsorbed hydrogen (H*). The systematic studies on reaction kinetics and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy under different conditions, including various temperatures, illumination powers, and feeding gas compositions, reveal the reaction mechanism responsible for CO methanation and the role of photoillumination.
将一氧化碳选择性加氢生成甲烷依赖于能够促进一氧化碳键断裂和氢解离吸附的合适催化剂。负载在二氧化硅纳米球上的超细铑纳米颗粒被用作一类光催化剂，以在宽带可见光源照射下显著提高由一氧化碳和氢气混合物生成甲烷的选择性和反应速率。二氧化硅纳米球中的强光散射共振在二氧化硅表面附近产生强电场，以增强负载的超细铑纳米颗粒中的光吸收能力，促进铑纳米颗粒中热电子的产生效率。热电子与铑纳米颗粒表面吸附物种的相互作用削弱了碳 - 氧键，以促进一氧化碳的脱氧，有利于在表面吸附氢（H*）存在的情况下以更快的速率以单一选择性生成甲烷。在不同条件下，包括各种温度、光照功率和进料气体组成，对反应动力学和漫反射红外傅里叶变换（DRIFT）光谱的系统研究揭示了负责一氧化碳甲烷化的反应机理和光照射的作用。
