Electrocatalytic CO₂ reduction has the dual-promise of neutralizing carbon emissions in the near future, while providing a long-term pathway to create energy-dense chemicals and fuels from atmospheric CO₂. The field has advanced immensely in recent years, taking significant strides towards commercial realization. Catalyst innovations have played a pivotal role in these advances, with a steady stream of new catalysts providing gains in CO₂ conversion efficiencies and selectivities of both C1 and C2 products. Comparatively few of these catalysts have been tested at commercially-relevant current densities (∼200 mA cm⁻²) due to transport limitations in traditional testing configurations and a research focus on fundamental catalyst kinetics, which are measured at substantially lower current densities. A catalyst's selectivity and activity, however, have been shown to be highly sensitive to the local reaction environment, which changes drastically as a function of reaction rate. As a consequence of this, the surface properties of many CO₂ reduction catalysts risk being optimized for the wrong operating conditions. The goal of this perspective is to communicate the substantial impact of reaction rate on catalytic behaviour and the operation of gas-diffusion layers for the CO₂ reduction reaction. In brief, this work motivates high current density catalyst testing as a necessary step to properly evaluate materials for electrochemical CO₂ reduction, and to accelerate the technology toward its envisioned application of neutralizing CO₂ emissions on a global scale.

中文翻译：

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气体扩散电极上的 CO ₂减少量以及为什么必须在与商业有关的条件下评估催化性能†

电催化还原CO ₂具有在不久的将来中和碳排放的双重承诺，同时提供了从大气中CO ₂产生能量密集的化学物质和燃料的长期途径。近年来，该领域取得了巨大的进步，朝着商业实现迈出了重要的步伐。催化剂创新在这些进展中起着举足轻重的作用，源源不断的新型催化剂可提高C1和C2产品的CO ₂转化效率和选择性。这些催化剂中很少有在与商业相关的电流密度（〜200 mA cm ^-2）下进行过测试的）是由于传统测试配置中的运输限制以及对基本催化剂动力学的研究所致，这些动力学是在实质上较低的电流密度下测得的。然而，已表明催化剂的选择性和活性对局部反应环境高度敏感，该局部反应环境随反应速率而急剧变化。结果，许多CO ₂还原催化剂的表面性能可能会因错误的操作条件而被优化。该观点的目的是传达反应速率对CO ₂催化行为和气体扩散层操作的重大影响还原反应。简而言之，这项工作激发了高电流密度催化剂测试的必要步骤，以正确评估用于电化学还原CO _2的材料，并加速该技术朝着其在全球范围内中和CO ₂排放的预期应用的方向发展。