Yang Hengpan, Wu Yu, Lin Qing, Fan Liangdong, Chai Xiaoyan, Zhang Qianling, Liu Jianhong, He Chuanxin, Lin Zhiqun
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, China.
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Angew Chem Int Ed Engl. 2018 Nov 19;57(47):15476-15480. doi: 10.1002/anie.201809255. Epub 2018 Oct 25.
A facile route to scalable production of N and S co-doped, hierarchically porous carbon nanofiber (NSHCF) membranes (ca. 400 cm membrane in a single process) is reported. As-synthesized NSHCF membranes are flexible and free-standing, allowing their direct use as cathodes for efficient electrochemical CO reduction reaction (CO RR). Notably, CO with 94 % Faradaic efficiency and -103 mA cm current density are readily achieved with only about 1.2 mg catalyst loading, which are among the best results ever obtained by metal-free CO RR catalysts. On the basis of control experiments and DFT calculations, such outstanding CO Faradaic efficiency can be attributed to the co-doped pyridinic N and carbon-bonded S atoms, which effectively decrease the Gibbs free energy of key *COOH intermediate. Furthermore, hierarchically porous structures of NSHCF membranes impart a much higher density of accessible active sites for CO RR, leading to the ultra-high current density.
报道了一种简便的方法，可规模化生产氮和硫共掺杂的分级多孔碳纳米纤维（NSHCF）膜（单次制备约400平方厘米的膜）。合成后的NSHCF膜具有柔韧性且可独立支撑，使其能够直接用作高效电化学CO还原反应（CO RR）的阴极。值得注意的是，仅约1.2毫克的催化剂负载量就能轻松实现法拉第效率为94%且电流密度为-103毫安/平方厘米的CO，这是无金属CO RR催化剂所取得的最佳结果之一。基于对照实验和DFT计算，如此出色的CO法拉第效率可归因于共掺杂的吡啶氮和碳键合硫原子，它们有效降低了关键*COOH中间体的吉布斯自由能。此外，NSHCF膜的分级多孔结构为CO RR提供了更高密度的可及活性位点，从而实现了超高电流密度。
