Rabiee Hesamoddin, Zhang Xueqin, Ge Lei, Hu Shihu, Li Mengran, Smart Simon, Zhu Zhonghua, Yuan Zhiguo
Advanced Water Management Centre, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia.
Centre for Future Materials, University of Southern Queensland, Springfield Central, Queensland 4300, Australia.
ACS Appl Mater Interfaces. 2020 May 13;12(19):21670-21681. doi: 10.1021/acsami.0c03681. Epub 2020 Apr 30.
The efficient CO electrochemical reduction reaction (CORR) relies not only on the development of selective/active catalysts but also on the advanced electrode configuration to solve the critical issue of poor CO mass transport and derived sluggish cathodic reaction kinetics. In this work, to achieve a favorable reaction rate and product selectivity, we designed and synthesized an asymmetric porous Cu hollow fiber gas diffusion electrode (HFGDE) with controlled Sn surface electrodeposition. The HFGDE derived from the optimal Sn electrodeposition condition exhibited a formate Faradaic efficiency (FE) of 78% and a current density of 88 mA cm at -1.2 V versus reversible hydrogen electrode, which are more than 2 times higher than those from the pristine Cu HFGDE. The achieved performance outperformed most of the other Sn-based GDEs, indicating the creation of sufficient contact among CO, electrolyte, and electrode catalyst through the design of the hollow fiber pore structure and catalytic active sites. The enhancement of formate production selectivity and the suppression of the hydrogen by-product were attributed to the optimized ratio of SnO species on the electrode surface. The best performance was seen in the HFGDE with the highest Sn/Sn (120 s deposition), likely due to the modulating effect of the Cu substrate via electron donation with Sn species. The selectivity control strategy developed in the asymmetric HFGDE provides an efficient and facile method to stimulate selective electrochemical reactions in which the gas-phase reactant with low solubility is involved.
高效的一氧化碳电化学还原反应（CORR）不仅依赖于选择性/活性催化剂的开发，还依赖于先进的电极结构，以解决一氧化碳传质差和由此导致的阴极反应动力学迟缓这一关键问题。在这项工作中，为了实现良好的反应速率和产物选择性，我们设计并合成了一种通过控制锡表面电沉积的不对称多孔铜中空纤维气体扩散电极（HFGDE）。在相对于可逆氢电极-1.2 V的条件下，源自最佳锡电沉积条件的HFGDE表现出78%的甲酸盐法拉第效率（FE）和88 mA cm的电流密度，这比原始铜HFGDE高出两倍以上。所实现的性能优于大多数其他基于锡的气体扩散电极（GDE），表明通过中空纤维孔结构和催化活性位点的设计，一氧化碳、电解质和电极催化剂之间形成了充分的接触。甲酸盐生成选择性的提高和氢气副产物的抑制归因于电极表面氧化锡物种的优化比例。在具有最高Sn/Sn（120 s沉积）的HFGDE中观察到了最佳性能，这可能是由于铜基底通过与锡物种的电子给予产生的调节作用。在不对称HFGDE中开发的选择性控制策略提供了一种有效且简便的方法，以促进涉及低溶解度气相反应物的选择性电化学反应。
