Guo Si-Xuan, Zhang Ying, Zhang Xiaolong, Easton Christopher D, MacFarlane Douglas R, Zhang Jie
School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia.
ARC Centre of Excellence for Electromaterials Science, Monash University, Clayton, Victoria, 3800, Australia.
ChemSusChem. 2019 Mar 7;12(5):1091-1100. doi: 10.1002/cssc.201802409. Epub 2019 Feb 7.
Oxides containing two-dimensional metallic catalysts have shown enhanced catalytic activity, stability, and product selectivity. Porous three-dimensional structures maximize the accessibility of the active sites, thus enhancing the catalytic performance of the catalysts. By integrating these desirable features in a single catalyst, further improvement in catalytic activity and selectivity is expected. In this study, oxide-containing bismuth (Bi) nanosheets of about 4 nm thickness interconnected to form a porous three-dimensional structure were synthesized by electrodeposition in the presence of phosphomolybdic acid under hydrogen evolution conditions. These Bi nanosheets catalyze CO reduction in a CO -saturated 0.5 m NaHCO solution to formate with a faradaic efficiency of 93±2 % at -0.86 V vs. RHE with a formate partial current density as high as 30 mA cm . The Tafel slope of about 78 mV dec suggests that the protonation of the adsorbed CO is the rate-limiting step.
含有二维金属催化剂的氧化物已表现出增强的催化活性、稳定性和产物选择性。多孔三维结构使活性位点的可及性最大化，从而提高了催化剂的催化性能。通过将这些理想特性整合到单一催化剂中，有望进一步提高催化活性和选择性。在本研究中，在析氢条件下，通过在磷钼酸存在下进行电沉积，合成了厚度约为4 nm的含氧化物铋（Bi）纳米片，这些纳米片相互连接形成多孔三维结构。这些Bi纳米片在-0.86 V（相对于可逆氢电极）下催化CO在CO饱和的0.5 m NaHCO溶液中还原为甲酸盐，法拉第效率为93±2 %，甲酸盐分电流密度高达30 mA cm 。约78 mV dec的塔菲尔斜率表明，吸附的CO 的质子化是速率限制步骤。
