Among various products from electrocatalytic CO₂ reduction (CO₂ER), HCOOH is highly profitable one. However, the slow kinetics of anodic oxygen evolution reaction lowers overall energy efficiency, which can be replaced by an electro-oxidation reaction with low thermodynamic potential and fast kinetics. Herein, we report an electrolysis system coupling CO₂ER with 5-hydroxymethylfurfural oxidation reaction (HMFOR). A BiOCl–CuO catalyst was designed to sustain CO₂ER to HCOOH at partial current density of 500 mA/cm² with FE_HCOOH above 90% and 700 mA/cm² with FE_HCOOH above 80%. In situ and ex situ x-ray absorption fine structure was used to capture the structure transform of BiOCl–CuO into metallic Bi and Cu during CO₂ER process, and the presence of CuO will promote this transformation which are supported by DFT calculations. Coupling HMFOR with CO₂ER, we realize both FE_HCOOH and FE_FDCA above 95% simultaneously, providing new prospects vista for the electrosynthesis of value-added products from paired system.

中文翻译：

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使用流通池高效电催化 CO2 还原为 HCOOH 与 5-羟甲基糠醛氧化偶联


在电催化CO ₂还原(CO ₂ ER)的各种产品中，HCOOH是利润最高的一种。然而，阳极析氧反应的缓慢动力学降低了整体能量效率，这可以被热力学势低、动力学快的电氧化反应所取代。在此，我们报道了一种将CO ₂ ER与5-羟甲基糠醛氧化反应（HMFOR）耦合的电解系统。 BiOCl-CuO催化剂被设计为在500 mA/cm ²的部分电流密度（FE _HCOOH高于90%）和700 mA/cm ² （FE _HCOOH高于80%）下维持CO ₂ ER至HCOOH。原位和异位X射线吸收精细结构被用来捕获CO ₂ ER过程中BiOCl-CuO向金属Bi和Cu的结构转变，并且CuO的存在将促进这种转变，这得到了DFT计算的支持。将HMFOR与CO ₂ ER耦合，同时实现FE _HCOOH和FE _FDCA都在95%以上，为配对体系电合成高附加值产品提供了新的前景。