Introducing tetrazole moiety to the ligand framework of two isomeric ruthenium catalysts, cis/trans-[Ru(tpy)(mtzp)(CH₃CN)]²⁺ (tpy = 2,2′:6′,2′'-terpyridine, mtzp = 2-(1-methyl-1H-tetrazol-5-yl)pyridine), for the electrochemical reduction of CO₂ to CO has altered the catalytic pathway with significantly low overpotential (0.37 V) compared to its analogous catalysts. Without manipulating steric effects, only the electronic nature of tetrazole moiety enables CO₂ binding to ruthenium center to form metallocarboxylate intermediate just after one-electron reduction. This is the first synthesized isomeric pair of ruthenium complex follow ECE (E = electron transfer, C = chemical reaction) mechanism for electrocatalytic reduction of CO₂. By successful characterization of the Ru–CO intermediate with the help of ¹³C NMR, spectro-electrochemical studies and analysis of byproducts formed during the electrocatalysis, a mechanism of CO₂ reduction has been established in presence of water and anhydrous conditions which is further supported by density functional theory (DFT).

将四唑部分引入两种异构钌催化剂的配体框架，顺式/反式-[Ru(tpy)(mtzp)(CH ₃ CN)] ²⁺ (tpy = 2,2':6',2''-三联吡啶， mtzp = 2-(1-methyl-1H-tetrazol-5-yl)pyridine)，用于将 CO ₂电化学还原为 CO改变了催化途径，与类似的催化剂相比，过电势显着低 (0.37 V)。在不操纵空间效应的情况下，只有四唑部分的电子性质使 CO ₂在单电子还原后立即与钌中心结合形成金属羧酸盐中间体。这是第一个合成的钌络合物的异构体对，其遵循ECE（E = 电子转移，C = 化学反应）机制用于CO _{2 的}电催化还原。借助¹³ C NMR、光谱电化学研究和分析电催化过程中形成的副产物，成功表征了 Ru-CO 中间体，建立了在水和无水条件下的CO ₂还原机制，进一步支持通过密度泛函理论（DFT）。