Yan Shenglin, Mahyoub Samah A, Lin Jing, Zhang Chunxiao, Hu Qing, Chen Chengzhen, Zhang Fanghua, Cheng Zhenmin
State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
Nanotechnology. 2021 Dec 28;33(12). doi: 10.1088/1361-6528/ac4287.
Noble metal aerogels (NMAs) have been used in a variety of (photo-)electrocatalytic reactions, but pure Au aerogel (AG) has not been used in COelectroreduction to date. To explore the potential application in this direction, AG was prepared to be used as the cathode in COelectroreduction to CO. However, the gelation time of NMAs is usually very long, up to several weeks. Here, an excess NaBHand turbulence mixing-promoted gelation approach was developed by introducing magnetic stirring as an external force field, which therefore greatly shortened the formation time of Au gels to several seconds. The AG-3 (AG with Au loading of 0.003 g) exhibited a high CO Faradaic efficiency (FE) of 95.6% at an extremely low overpotential of 0.39 V, and over 91% of CO FE was reached in a wide window of -0.4 to -0.7 V versus the reversible hydrogen electrode (RHE). Partial current density in CO was measured to be -19.35 mA cmat -0.8 V versus RHE under 1 atm of CO. The excellent performance should be ascribed to its porous structure, abundant active sites, and large electrochemical active surface area. It provides a new method for preparation of AG with ultrafast gelation time and large production at room temperature, and the resulting pure AG was for the first time used in the field of COelectroreduction.
贵金属气凝胶（NMA）已被用于各种（光）电催化反应，但纯金气凝胶（AG）迄今为止尚未用于CO电还原反应。为了探索在这个方向上的潜在应用，制备了AG用作CO电还原为CO的阴极。然而，NMA的凝胶化时间通常很长，长达数周。在此，通过引入磁力搅拌作为外力场，开发了一种过量硼氢化钠和湍流混合促进凝胶化的方法，从而将金凝胶的形成时间大大缩短至几秒。AG-3（金负载量为0.003 g的AG）在0.39 V的极低过电位下表现出95.6%的高CO法拉第效率（FE），并且相对于可逆氢电极（RHE）在-0.4至-0.7 V的宽窗口内达到了超过91%的CO FE。在1 atm的CO气氛下，相对于RHE，在-0.8 V时测得的CO分电流密度为-19.35 mA cm²。其优异的性能应归因于其多孔结构、丰富的活性位点和大的电化学活性表面积。它提供了一种在室温下以超快凝胶化时间和大规模生产制备AG的新方法，并且所得到的纯AG首次用于CO电还原领域。
