Electrochemical reduction of CO₂ is a promising strategy to manage the global carbon balance by transforming CO₂ into chemicals. The efficiency of CO₂ electroreduction is largely dependent on the design of hybrid electrode where both support and catalyst govern the performance of the electrolyzer. In this work, TiO₂ calcined at different temperatures, was used as a support for immobilization of cobalt tetraphenyl porphyrin (CoTPP) and its effect on CO₂ reduction was studied. It is demonstrated that the crystalline phase of TiO₂ and doping of TiO₂ apparently affecting CO₂ electroreduction. It is found that anatase phase exhibits higher activity and selectivity compared to rutile due to the enhanced conductivity which in turn enables faster electron transfer between the support and CoTPP. As for dopants, the carbon doping in anatase TiO₂ is proven to further enhance its conductivity, consequently resulting in the enhanced performance. This study implies that the rational design of supports is important for the performance of the hybrid electrode towards electrochemical CO₂ reduction.

电化学还原CO ₂是通过将CO ₂转化为化学物质来管理全球碳平衡的一种有前途的策略。CO ₂电解还原的效率在很大程度上取决于混合电极的设计，在混合电极中，载体和催化剂共同控制着电解器的性能。在这项工作中，将在不同温度下煅烧的TiO ₂用作固定化四苯基卟啉钴（CoTPP）的载体，并研究了其对CO ₂还原的影响。已经证明，TiO 2的结晶相₂和TiO的掺杂₂显然影响CO ₂电还原。发现与金红石相比，锐钛矿相具有更高的活性和选择性，这归因于电导率的提高，这反过来又使得支持体和CoTPP之间的电子转移更快。对于掺杂剂，已证明锐钛矿型TiO _2中的碳掺杂可进一步提高其导电性，从而提高性能。该研究表明，载体的合理设计对于混合电极对电化学CO ₂还原的性能至关重要。