Electrochemical CO reduction reaction (CORR) to formic acid is a much-anticipated way of converting excess CO to high-value-added products. Bismuth (Bi)-based materials are promising catalysts, but remain challenging in terms of activity and selectivity. Herein, we reported a composition manipulation strategy to achieve simultaneous high activity and selectivity for CORR towards formate by incorporating Lewis acid CrO into Bi. Specifically, a novel Bi-CrO crystalline-amorphous catalyst was prepared by electroreduction of bismuth chromate (Bi(CrO)). The as-prepared catalyst shows nano-dendrites structure, promising the maximum exposure of active sites. The obtained Bi-CrO catalyst exhibits a high Faradic efficiency (FE, 93.3 %) at −1.1 V vs reversible hydrogen electrode (RHE), and can achieve a remarkable current density of −40.7 mA cm at the same potential. Meanwhile, the FE remains above 90 % over a wide potential window (−0.8 ∼ −1.2 V vs RHE) and the stability can maintain for 13 h at −0.9 V vs RHE with high selectivity (>90 %) and stable physical phase. Furthermore, the Zn-CO battery assembled with a Bi-CrO catalyst achieves the greatest power density of 4.63 mW cm and could maintain cyclic charge/discharge stability for 40 h.

中文翻译：

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Cr2O3 促进 Bi 基催化剂电化学 CO2 还原为 HCOOH 的催化性能

电化学 CO 还原反应 (CORR) 生成甲酸是将过量 CO 转化为高附加值产品的一种备受期待的方法。铋（Bi）基材料是有前途的催化剂，但在活性和选择性方面仍然具有挑战性。在此，我们报道了一种成分控制策略，通过将路易斯酸 CrO 掺入 Bi 中，同时实现 CO2RR 对甲酸盐的高活性和选择性。具体而言，通过铬酸铋（Bi(CrO)）的电还原制备了一种新型Bi-CrO晶体非晶态催化剂。所制备的催化剂显示出纳米枝晶结构，有望最大程度地暴露活性位点。所得Bi-CrO催化剂在-1.1 V vs 可逆氢电极（RHE）下表现出高法拉第效率（FE，93.3%），并且在相同电位下可以实现-40.7 mA cm的显着电流密度。同时，在较宽的电位窗口（-0.8 ∼ -1.2 V vs RHE）内，FE 保持在 90% 以上，并且在 -0.9 V vs RHE 下稳定性可以保持 13 小时，具有高选择性（> 90 %）和稳定的物理相。此外，与Bi-CrO催化剂组装的Zn-CO电池实现了4.63 mW cm的最大功率密度，并且可以保持40小时的循环充放电稳定性。