Xi Cao,Shan Ren,Xue Zhang,Qikui Fan,Qingqing Chen,Jian Yang,Junjie Mao
Cu-based catalysts are boosting electrocatalysts in CO 2 reduction reactions to high-value multicarbon (C 2+ ) products. Because of the unstable Cu + species and the unclear microscopic structure in reactions, Cu-based catalysts still face significant challenges of low selectivity and poor durability at high current density. Herein, we report a thermodynamically driven comproportionation strategy for forming a Cu 0 /Cu + /Cu 0 interface to stabilize Cu + species. When tested in a flow cell containing neutral electrolyte, the sample showed a high C 2+ products Faradaic efficiency (FE C2+ ) of 92.3% at a partial current density of 276.9 mA cm −2 . In a membrane electrode assembly, the sample achieved a 90.1% FE C2+ and maintained continuous operation for over 50 h at industrial current density. Further investigation demonstrates outstanding FE C2+ of >80% at a large industrial current of 10 A. Mechanism studies reveal that the Cu 0 /Cu + /Cu 0 interface lowers the energy barrier for C–C coupling in the reaction, thus facilitating the conversion of CO 2 to C 2+ products.
Xiuting Wu,Zefeng Zheng,Liang Ma,Changsong Hu,Yunhong Pi,Tiejun Wang
The aqueous-phase reforming of methanol(APRM)via non-precious metal heterogeneous catalysts is highly desirable, but challenging. Herein, we report a highly efficient copper catalyst encapsulated by chitosan-glucose (CS-G) conjugate with high metal loading of 35 wt% for H 2 generation from APRM. The optimized Cu@CS 19 -G 1 -300 catalyst exhibited exceptional activity of 1.39 × 10 5 μmol H2 /g cat /h at low temperature of 210 °C, which was ∼4.5 times higher than that of commercial CuZrAl catalysts (2.88 × 10 4 μmol H2 g cat −1 h −1 ). The chitosan-glucose conjugate acted not only as the main carbon support for Cu dispersion, but also as adsorbent to stablize as many Cu ions as possible. And meanwhile, with abundant Cu + /Cu 0 interface sites due to the reducing effect of glucose, the water gas shift reaction (WGSR) was intensified and thus displayed excellent selectivity toward CO by-product. This specific catalyst construction for H 2 production from APRM exhibits great potential of on-site H 2 supply for polymer membrane fuel cells.
危险品化学品经营许可证（带存储）