层状双金属氧化物表面修饰TiO2增强光催化CO2还原及作用机制研究

项目名称： 层状双金属氧化物表面修饰TiO2增强光催化CO2还原及作用机制研究

项目编号： No.51502078

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 种瑞峰

作者单位： 河南大学

项目金额： 21万元

中文摘要： 光催化CO2还原为碳氢化合物是解决环境问题和实现碳的循环利用理想途径之一。从CO2的光催化还原反应过程来看，其决速步骤是CO2经过单电子转移形成激发态CO2·-的过程。该过程的反应能垒最高(－1.9V vs NHE)，绝大多数半导体都不具有足够负的导带电子，导致CO2的光催化还原效率较低。通过增强CO2与催化剂间的相互作用，实现CO2在催化剂表面的吸附活化，可以有效降低CO2单电子转移所需克服的能垒，提高CO2的光催化还原效率。层状双金属氧化物(LDOs)具有较强表观碱性，对CO2表现了很强的吸附活化能力。本项目拟采用LDOs表面包覆TiO2制备LDOs/TiO2核壳复合催化剂，研究光生电子在助催化与LDOs、LDOs与TiO2界面的传输机制，探索LDOs吸附活化增强CO2光催化还原的机理。研究结果将为开发高效的CO2还原光催化剂提供有益的借鉴，对实现CO2向高附加值燃料的转化有重要意义。

中文关键词： 光催化CO2还原；层状双金属氧化物；TiO2；CO2·-；CO2；吸附

英文摘要： Photocatalytic reduction of CO2 to hydrocarbon fuels is a promising solution for the global warming and can realize the recyclable utilization of carbon materials. In view of the mechanism of photocatalytic reduction of CO2, the rate-limiting step is the formation of CO2·- from CO2 via a single electron transfer process. The barrier of such process is as high as -1.9 V vs NHE, so most of semiconductors could not provide such negative conducting electrons, resulting in a lower photocatalytic reduction efficiency of CO2. By enhancing the interaction between CO2 and photocatalyst, CO2 could be activated and then the barrier could be decreased, thus benefits photocatalytic reduction efficiency of CO2. Layered double metal oxides (LDOs) with strong apparent alkaline demonstrate powerful activation of CO2. In this project, we aim to prepare LDOs coated TiO2 for the photocatalytic reduction of CO2. The investigation will focus on the transfer mechanism of photo-generated electron between the interfaces of cocatalyst/LDOs and LDOs/TiO2, as well as the mechanism of enhancing photocatalytic reduction of CO2 by LDOs adsorption activation. The results will be beneficial for the development of highly efficient photocatalysts for photocatalytic reduction of CO2, with great importance of the conversion of CO2 to value-added fuels.

英文关键词： photocatalytic CO2 reduction ;Layered double metal oxides ;TiO2;CO2·-;CO2 adsorption