The electrochemical reduction of CO₂ to formate and formic acid has attracted a great amount of academic and commercial interest over the past five years. A number of experimental studies have generated data on the Faradaic performance and stability of various candidate catalyst materials in producing formate or formic acid. However, most of the data has been conducted at low current densities and over short time periods, typically hours to days. There is a critical need in providing long-term catalyst stability as well as electrolyzer-based operating data, which are needed for the commercial scale-up and operation of this technology, especially at high current densities. In this paper, the electrochemical CO₂ conversion to pure formic acid was conducted using a three-compartment design electrolyzer, demonstrating electrolyzer catalyst and performance stability for over 1000 h at current densities up to 200 mA cm⁻². Depending on the operation conditions, the electrolyzer directly produced a 6.03–12.92 wt% (1.3–2.8 M) formic acid product at Faradaic efficiencies ranging between 73.0–91.3%. Data on electrolyzer performance, including formic acid product generation rate, energy efficiency, and energy consumption are reported at three different current densities, 100, 200, and 250 mA cm⁻². Lastly, a long term 1000 h electrolyzer stability run at 200 mA cm⁻² is presented, providing information on the operating conditions required in obtaining stable electrolyzer performance. All the data will be extremely useful in the commercial scale-up of this technology.

在过去的五年中，CO ₂的电化学还原为甲酸和甲酸引起了广泛的学术和商业兴趣。许多实验研究已经产生了有关法拉第性能和各种候选催化剂材料在生产甲酸或甲酸中的稳定性的数据。但是，大多数数据是在低电流密度和短时间段（通常为数小时至数天）内进行的。迫切需要提供长期的催化剂稳定性以及基于电解器的运行数据，这对于该技术的商业规模化生产和运行（尤其是在高电流密度下）是必需的。本文介绍了电化学CO ₂使用三室设计的电解槽将其转化为纯甲酸，证明该电解槽催化剂在电流密度高达200 mA cm ^{-2的条件下}可保持1000小时以上的性能。根据运行条件，电解器可直接产生6.03–12.92 wt％（1.3–2.8 M）的甲酸产品，法拉第效率为73.0–91.3％。在三种不同的电流密度（100、200和250 mA cm ^-2）下报告了有关电解器性能的数据，包括甲酸产物的生成速率，能效和能耗。最后，长期的1000小时电解槽稳定性在200 mA cm ^-2下运行本文介绍了如何提供稳定的电解槽性能所需的工作条件信息。所有数据对于该技术的商业规模推广都是极为有用的。