钯铋双金属纳米材料的可控制备及电催化CO2还原应用研究

Electrochemical CO2 reduction combined with renewable energy resources represents one of the promising strategies for not only reducing greenhouse gas emissions, but also storing electrical energy in a value-added chemical form. Among the products, HCOO- is considered as a valuable liquid chemical for hydrogen storage because it can release the H2 fuel responsibly at room temperature. The Pd metal is the only electrocatalyst that produces HCOO- at a zero-overpotential with high selectivity. However, a key challenge is how to minimize or prevent the catalyst degradation caused by CO poisoning. Previous approaches have focused mostly on developing catalysts that favor the HCOO- production over CO adsorption. Although the degradation rate was lowered via the catalyst development, the stability issue has not been fully resolved yet. In order to effectively solve the above problems, the applicant intends to develop palladium-bismuth bimetallic nanomaterials for electrocatalytic CO2 reduction, which benefits from the strong anti-CO poisoning ability of the bismuth-based materials to regulate the binding ability of the reaction intermediates on the catalyst surface. Therefore, the activity and stability of the reduction of CO2 in the palladium-based material are effectively improved. By exploring the composition, size, morphology and surface electronic structure of the catalysts to obtain the best catalytic performance.

利用电化学方法将CO2还原转化为高附加值化学品，被认为是目前最具有应用前景的CO2转化技术之一。钯是目前唯一能够在接近零过电位下实现高选择性地转化CO2生成甲酸的电极材料，但由于CO的毒化作用导致钯催化剂的稳定性通常很不理想。铋是一种具有较强抗CO毒化能力的金属材料，借助于铋优异的电催化特质，采用在钯催化剂体系中引入第二类金属铋的调控策略，通过改变催化剂的电子构型，从而削弱反应中间体CO*在催化剂表面的吸附能力，以实现增强催化剂抗CO毒化能力的目的。本项目中，申请人拟发展高效的钯铋双金属纳米材料, 通过调控钯、铋两种金属之间的组成、比例、尺寸、晶面和微观结构等特征，系统地研究电化学CO2还原的催化性能，探索钯铋双金属材料内在结构与电催化性能之间的作用机制，建立良好的构效关系，为进一步设计和制备高效CO2还原催化剂提供了一种切实可行的研究方案，具有重要的研究价值与科学意义。

利用可再生能源（如太阳能、风能等）驱动的电催化CO2还原反应（CO2RR）因具有温和的反应条件、相对较高的转化效率和广阔的实用前景而备受青睐。相比于乙烯、乙醇、丙醇等其它产物，利用电化学CO2还原技术生产甲酸是目前最具经济可行性的方案。钯（Pd）是目前唯一已知能够在接近零过电势下实现CO2还原生成甲酸的催化材料。然而，Pd基催化材料极易受到CO毒化成为制约其应用发展的主要难题。本项目发展了一系列高效高稳定的钯基双金属纳米材料，通过调控钯与第二种金属之间的组成、比例、尺寸、晶面和微观结构等特征，系统地研究电化学CO2还原的催化性能，探索钯基双金属材料内在结构与电催化性能之间的作用机制，建立良好的构效关系，为进一步设计和制备高效CO2还原催化剂提供了一种切实可行的研究方案。项目执行期间，在Nature Communications、Energy & Environmental Science、Advanced Materials、Angew. Chem. Int. Ed.等高水平杂志发表学术论文12篇，授权中国专利1项，获江苏省高等学校科学技术研究成果二等奖。项目先后资助硕士研究生8人、博士研究生3人。