Electrochemical reduction of CO₂ is a promising route for sustainable production of fuels. A grand challenge is developing low-cost and efficient electrocatalysts that can enable rapid conversion with high product selectivity. Here we design a series of nickel phthalocyanine molecules supported on carbon nanotubes as molecularly dispersed electrocatalysts (MDEs), achieving CO₂ reduction performances that are superior to aggregated molecular catalysts in terms of stability, activity and selectivity. The optimized MDE with methoxy group functionalization solves the stability issue of the original nickel phthalocyanine catalyst and catalyses the conversion of CO₂ to CO with >99.5% selectivity at high current densities of up to −300 mA cm⁻² in a gas diffusion electrode device with stable operation at −150 mA cm⁻² for 40 h. The well-defined active sites of MDEs also facilitate the in-depth mechanistic understandings from in situ/operando X-ray absorption spectroscopy and theoretical calculations on structural factors that affect electrocatalytic performance.

电化学还原CO ₂是可持续生产燃料的有希望的途径。一个巨大的挑战是开发低成本，高效的电催化剂，以实现高转化率和高产品选择性。在这里，我们设计了一系列负载在碳纳米管上的镍酞菁镍分子作为分子分散的电催化剂（MDE），在稳定性，活性和选择性方面，CO ₂还原性能均优于聚集的分子催化剂。具有甲氧基官能团的优化MDE解决了原始镍酞菁镍催化剂的稳定性问题，并在高达-300 mA cm ^-2的高电流密度下以大于99.5％的选择性催化了CO ₂到CO的转化。在气体扩散电极装置中，在-150mA cm ^-2下稳定运行40小时。MDE的明确定义的活性位点还有助于从原位/操作X射线吸收光谱学以及对影响电催化性能的结构因素进行理论计算的深入机理理解。