利用可再生能源驱动CO₂电化学还原制增值产品可实现人工碳循环和洁净电能的高效存储，是实现碳中和战略目标的重要策略。铜基催化剂是迄今为止唯一可实现CO2电化学还原制取多种产物的催化剂，但其面临CO₂电化学还原过电势高和产物选择性低等挑战。为提升铜基催化剂CO₂电化学还原性能，采用模板剂辅助水热合成法制备纳米CuO催化剂，探究聚乙烯吡咯烷酮(PVP)模板剂添加量对CuO催化剂微观结构和CO₂电化学还原性能的影响。结果表明，添加PVP直接影响水热合成过程中CuO晶体成核与生长。CuO催化剂的平均粒径和CO2电化学还原性能依赖于PVP模板剂的添加量。PVP分子中的疏水碳链有利于使其保持分子斥力，抑制CuO催化剂纳米颗粒聚并。随PVP含量提高，CuO催化剂平均粒径先降低后增加，而其CO₂电化学还原性能先提高后降低。PVP质量分数为25%的CuO催化剂(CuO-PVP-25)的平均粒径最小(29.53 nm)，其在-0.53 V（可逆氢电极RHE）电势下，CO2电化学还原产物CO选择性和电流密度最高可达48.2%和-5.8 mA/cm²。CuO-PVP-25催化剂较佳的CO₂电化学还原性能得益于其较小的粒径，因其平均粒径降低可诱导产生大量不饱和位点，直接影响CuO催化剂表面对关键中间体*CO的结合能，显著影响其催化活性和产物选择性。

Electrochemical CO2 reduction (ECR) to value-added products using renewable electricity enables artificial carbon cycle and clean energy storage, which represents an important strategy to realize carbon neutrality. Copper-based catalysts have been recognized as the only materials that can realize the electrochemical reduction of CO2 to produce a variety of products. However, it faces the challenges of high overpotential and poor products selectivity in ECR. To promote the ECR performance of copper-based catalysts, template-assisted hydrothermal synthesis method was employed to synthesize CuO nanostructures, and the influence of the content of polyvinylpyrrolidone (PVP) template on the structure and ECR performance of CuO catalysts was demonstrated. The results indicate that the nucleation and growth of CuO crystals in hydrothermal synthesis can be affected due to the addition of PVP. The average particle size and ECR performance of the CuO catalysts depends on the content of the PVP template. The hydrophobic carbon chain in PVP endows the molecule with repulsive force, which has retarded the agglomeration of CuO nanostructures. With the increase in PVP content, the average particle size decreases first and then increases, while the ECR performance increases first and then declines. The desired CuO-PVP-25 catalyst with 25% PVP content shows the minimum average particle size of 29.53 nm. Under the given potential of -0.53 V，the CO selectivity and current density of CO2 electrochemical reduction products can reach up to 48.2% and -5.8 mA/cm2. The excellent ECR performance is associated with the particle size effect, as catalyst with minimized particle size offers more undercoordinated sites, which affects the binding energy of the catalyst surface towards the adsorption of the *CO intermediate, thus significantly affecting the catalytic activity and products selectivity.

0 引言

1 试验

   1.1 催化剂制备

   1.2 催化剂表征

   1.3 CO2电化学还原性能测试

2 结果与讨论

   2.1 PVP含量对CuO催化剂微观结构特性的影响

   2.2 PVP含量对CuO催化剂CO2电化学还原性能的影响

3 结论