Hossain M Nur, Ahmad Syed, da Silva Iranaldo Santos, Kraatz Heinz-Bernhard
Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, M1C1A4, Canada.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, M5S 3H6, Canada.
Chemistry. 2021 Jan 18;27(4):1346-1355. doi: 10.1002/chem.202003039. Epub 2020 Dec 15.
Electrocatalytic reduction of CO into usable chemicals is a promising path to address climate change and energy challenges. Herein, we demonstrate the synthesis of unique coinage metal (Cu, Ag, and Au) nanodendrites (NDs) via a facile galvanic replacement reaction (GRR), which can be effective electrocatalysts for the reduction of CO in an ethanolamine (EA) solution. Each metal ND surface was directly grown on glassy-carbon (GC) substrates from a mixture of Zn dust and the respective precursor solution. The electrocatalytic activities of the synthesized ND surfaces were optimized for CO reduction in EA solution by varying their composition. It was determined that a 0.05 mol fraction of EA exhibited the highest catalytic activity for all metal NDs. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) techniques showed that metal-ND electrodes possessed higher current densities, lower onset potentials and lower charge-transfer resistances for CO reduction than their smooth polycrystalline electrode counterparts, indicating improved CO reduction catalytic activity. It was determined, using FTIR and NMR spectroscopy, that formate was produced as a result of the CO reduction.
将CO电催化还原为可用化学品是应对气候变化和能源挑战的一条有前景的途径。在此，我们展示了通过简便的电置换反应（GRR）合成独特的硬币金属（Cu、Ag和Au）纳米枝晶（NDs），其可作为乙醇胺（EA）溶液中CO还原的有效电催化剂。每种金属ND表面都由锌粉和各自的前驱体溶液混合物直接生长在玻碳（GC）基底上。通过改变合成的ND表面的组成，优化了其在EA溶液中对CO还原的电催化活性。确定0.05摩尔分数的EA对所有金属NDs表现出最高的催化活性。线性扫描伏安法（LSV）和电化学阻抗谱（EIS）技术表明，与光滑的多晶电极相比，金属-ND电极在CO还原方面具有更高的电流密度、更低的起始电位和更低的电荷转移电阻，表明CO还原催化活性得到了改善。使用傅里叶变换红外光谱（FTIR）和核磁共振光谱（NMR）确定，CO还原产生了甲酸盐。
