摘要
电催化二氧化碳还原反应可以将二氧化碳转化为一氧化碳、甲烷、甲酸、乙醇、乙烯等具有高价值的化工原料,不仅可以减少二氧化碳的排放,而且为缓解能源危机指出了新的道路。铜是目前最常见的可将二氧化碳还原为多碳产物的金属催化剂,铜的部分氧化对于反应过程中间体的吸附有着重要的影响,但是在负电位的电解条件下会不可避免被还原,从而导致催化性能下降。通过将硼掺杂调节了铜的电子结构,使得铜的氧化态在反应前后保持稳定,提升了乙醇、乙烯等多碳产物的选择性。掺入硼的铜催化剂在-0.65 V(vs.RHE)时,所有C_(2)产物的法拉第效率总和达到80%,显著高于相同电位下的未掺杂硼的催化剂(43%)。以流动池为装置进行测试,极大地提升了电流密度,并且在-0.95 V(vs.RHE)时,C_(2)产物的法拉第效率达到34.15%,同时分电流密度达到132.7 mA·cm^(-2)。经过15 h稳定性测试后,在含有间隙硼的铜催化剂中,铜仍然可以保持多种价态存在。通过原位阻抗测试以及原位傅里叶变换红外光谱可知,硼的引入可以增加催化剂的氢吸附电阻,减小氢的覆盖度,同时增强C-C耦联,从而促进C_(2)产物的生成。
Electrocatalytic carbon dioxide reduction reactions can convert carbon dioxide into high-value chemical raw materials such as carbon monoxide,methane,formic acid,ethanol and ethylene,which not only can reduce carbon dioxide emissions,but also point a new way to alleviate the energy crisis.Copper is currently the most common metal catalyst that can reduce carbon dioxide to polycarbonate products.The partial oxidation of copper has an important effect on the adsorption of reaction process intermediates,but it will be inevitably reduced under electrolytic conditions with negative potentials,which leads to a decrease in catalytic performance.In this paper,we modulate the electronic structure of copper by doping boron into copper,which makes the oxidation state of copper stable before and after the reaction and enhances the selectivity of the multi-carbon products.The Faraday efficiency of the boron-doped copper catalyst at-0.65 V(vs.RHE)reached a sum of 80%for all C_(2)products,which was significantly higher than that of the undoped boron catalyst at the same potential(43%).Testing with a flow cell as the device greatly increased the current density and achieved a Faraday efficiency of 34.15%for the C_(2)products at-0.95 V(vs.RHE)along with a fractional current density of 132.7 mA·cm^(-2).After 15 h of stability testing,copper can remain in multiple valence states in copper catalysts containing boron.As shown by in situ impedance testing as well as in situ Fourier transform infrared spectroscopy,the introduction of boron can increase the hydrogen adsorption resistance of the catalyst and reduce the hydrogen coverage,while enhancing the C-C coupling,thus promoting the generation of C_(2)products.
作者
杜浩洋
杨宇
赖建平
王磊
Du Haoyang;Yang Yu;Lai Jianping;Wang Lei(College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;College of Environment and Safety Engineering,Qingdao University of Science and Technology,Qingdao 266042,China)
出处
《山东化工》
2023年第24期1-6,10,共7页
Shandong Chemical Industry
基金
国家自然科学基金(52272222,52072197,22110043)
山东省杰出青年基金(ZR2019JQ14)。
关键词
铜基催化剂
氧化态
二氧化碳还原反应
copper-based catalyst
oxidation state
carbon dioxide reduction reaction
