Molecular catalysts play a significant role in chemical transformations, utilizing changes in redox states to facilitate reactions. To date molecular electrocatalysts have efficiently produced single-carbon products from CO₂ but have struggled to achieve a carbon–carbon coupling step. Conversely, copper catalysts can enable carbon–carbon coupling, but lead to broad C₂₊ product spectra. Here we subvert the traditional redox-mediated reaction mechanisms of organometallic compounds through a heterogeneous nickel-supported iron tetraphenylporphyrin electrocatalyst, facilitating electrochemical carbon–carbon coupling to produce ethanol. This represents a marked behavioural shift compared with carbon-supported metalloporphyrins. Extending the approach to a three-dimensional porous nickel support with adsorbed iron tetraphenylporphyrin, we attain ethanol Faradaic efficiencies of 68% ± 3.2% at −0.3 V versus a reversible hydrogen electrode (pH 7.7) with partial ethanol current densities of −21 mA cm⁻². Separately we demonstrate maintained ethanol production over 60 h of operation. Further consideration of the wide parameter space of molecular catalyst and metal electrodes shows promise for additional chemistries and achievable metrics.

分子催化剂在化学转化中发挥着重要作用，利用氧化还原态的变化来促进反应。迄今为止，分子电催化剂已有效地从CO ₂生产单碳产物，但仍难以实现碳-碳偶联步骤。相反，铜催化剂可以实现碳-碳偶联，但会产生较宽的 C ₂₊产物谱。在这里，我们通过非均相镍负载铁四苯基卟啉电催化剂颠覆了有机金属化合物传统的氧化还原介导的反应机制，促进电化学碳碳偶联生产乙醇。与碳支撑的金属卟啉相比，这代表了显着的行为转变。将这种方法扩展到具有吸附的四苯基卟啉铁的三维多孔镍载体，与部分乙醇电流密度为-21 mA cm的可逆氢电极（pH 7.7）相比，在-0.3 V时，我们获得了68% ± 3.2%的乙醇法拉第效率。 ⁻² 。我们另外证明了在 60 小时的运行中维持乙醇生产。对分子催化剂和金属电极的广泛参数空间的进一步考虑显示了额外化学和可实现指标的希望。