研究人员采用了一种具有 CO2 对 CO 选择性的金电催化剂,研究了用几种无机阴离子和羧酸阴离子的钾盐代替碳酸氢盐电解液时的差异。利用原位差分电化学质谱法对生成的物种(H2 和 CO)进行了在线监测。与碳酸氢盐相比,无机阴离子高氯酸盐、硫酸盐和氯化物降低了 CO2 的还原率,但对 CO 的选择性也高于 H2,因为它们在工作 pH 值下是较差的质子供体。有趣的是,这三种无机阴离子的性能大致相似。相比之下,测试的一系列羧酸阴离子(丙酸根、乙酸根、甲酸根和三氟乙酸根)的性能则因所附分子的电子吸取或捐献特性不同而各异(如图)。分子动力学模拟将阴离子吸附能确定为二氧化碳还原动力学的描述因子,动力学的提高与吸附能的降低相关。因此,观察到的 CO 生成是二氧化碳还原速率(受阴离子吸附控制)和二氧化碳还原选择性(受阴离子碱性影响)之间的平衡。在所有测试物种中,丙酸盐由于表面吸附力弱和质子可用性低而被认为是最佳物种,在二氧化碳选择性方面以相似的速率优于碳酸氢盐。这篇报道强调了将电解质阴离子特性与阳离子一起纳入需要控制、优化并最终理解的参数列表的必要性,从而推动该领域的发展。
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Nature Catalysis serves as a platform for researchers across chemistry and related fields, focusing on homogeneous catalysis, heterogeneous catalysis, and biocatalysts, encompassing both fundamental and applied studies. With a particular emphasis on advancing sustainable industries and processes, the journal provides comprehensive coverage of catalysis research, appealing to scientists, engineers, and researchers in academia and industry.
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