PDF(Pubmed)
Abstract：
Precise electrochemical synthesis of commodity chemicals and fuels from CO2 building blocks provides a promising route to close the anthropogenic carbon cycle, in which renewable but intermittent electricity could be stored within the greenhouse gas molecules. Here, we report state-of-the-art CO2-to-HCOOH valorization performance over a multiscale optimized Cu-Bi cathodic architecture, delivering a formate Faradaic efficiency exceeding 95% within an aqueous electrolyzer, a C-basis HCOOH purity above 99.8% within a solid-state electrolyzer operated at 100 mA cm-2 for 200 h and an energy efficiency of 39.2%, as well as a tunable aqueous HCOOH concentration ranging from 2.7 to 92.1 wt%. Via a combined two-dimensional reaction phase diagram and finite element analysis, we highlight the role of local geometries of Cu and Bi in branching the adsorption strength for key intermediates like *COOH and *OCHO for CO2 reduction, while the crystal orbital Hamiltonian population analysis rationalizes the vital contribution from moderate binding strength of η2(O,O)-OCHO on Cu-doped Bi surface in promoting HCOOH electrosynthesis. The findings of this study not only shed light on the tuning knobs for precise CO2 valorization, but also provide a different research paradigm for advancing the activity and selectivity optimization in a broad range of electrosynthetic systems.
摘要：
从CO2构建块中精确电化学合成商品化学品和燃料提供了关闭人为碳循环的有希望的途径，其中可再生但间歇性的电力可以储存在温室气体分子中。这里,我们报告了在多尺度优化的Cu-Bi阴极结构上最先进的CO2到HCOOH的价值化性能，在水电解槽内提供超过95%的甲酸法拉第效率，以C为基础的HCOOH纯度高于99.8％，在100mAcm-2的固态电解槽中运行200小时，能量效率为39.2％，以及可调的水性HCOOH浓度范围为2.7至92.1wt%。通过结合二维反应相图和有限元分析，我们强调了Cu和Bi的局部几何形状在分支的关键中间体如*COOH和*OCHO用于CO2还原的吸附强度中的作用，而晶体轨道哈密顿种群分析合理化了η2的中等结合强度的重要贡献（O，Cu掺杂Bi表面O)-OCHO促进HCOOH电合成.这项研究的结果不仅揭示了精确的CO2增值的调谐旋钮，但也提供了一个不同的研究范式，推进活性和选择性优化在广泛的电合成系统。
