摘要
光能驱动CO_(2)还原技术有望减少CO_(2)排放并同时提供高价值化学燃料,缓解能源转型带来的压力。发展高活性光催化剂是实现该技术应用的关键,负载贵金属是提高其光催化效率的有效途径,但由于贵金属成本昂贵、储量稀少等原因,限制了其大规模使用。因此,发展贵金属替代品对光催化CO_(2)还原具有重要意义。Mo_(2)C是一种具有与贵金属相似的电子结构的过渡金属碳化物,采用尿素还原方式制备了Mo_(2)C和Cu共负载TiO_(2)光催化剂,结合物理化学性质分析,对其在紫外光下的光催化活性进行评价。结果表明,在TiO_(2)上负载Mo_(2)C后,在CO_(2)催化转化过程中显著促进H_(2)和CH_(4)的产生,而Mo_(2)C和Cu共沉淀可抑制H_(2)产生并促进CO_(2)进一步转化为CH_(4);光照4 h后,其CH_(4)累计产量达76.1μmol/g,为纯TiO_(2)的5.6倍。Cu沉积可促进CO_(2)吸附并抑制水蒸气吸附,从而减少H_(2)生成。Mo_(2)C和Cu的共沉积可有效减小TiO_(2)带隙宽度、抑制光生电子与空穴对的复合并促进光生电荷在催化剂表面的分离与转移,从而提高其光催化反应的活性。
Light-driven CO_(2) reduction technology is expected to reduce CO_(2) emissions and provides high-value chemical fuels at the same time to alleviate the pressure during energy transition.Among them,the development of highly active photocatalysts is the key to realize the application of this technology.Loading noble metals is an effective way to improve their photocatalytic efficiency.However,the high cost and scarce reserves of noble metals limit their large-scale use.Therefore,the development of precious metal substitutes is great significance for photocatalytic CO_(2) reduction.Mo_(2) C is a transition metal carbide with an electronic structure similar to that of noble metal.Mo_(2) C and Cu co-loaded TiO_(2) photocatalysts were prepared by urea reduction.Their photocatalytic activity under UV light was evaluated by combining physical and chemical properties analysis.The results show that after loading Mo_(2) C on TiO_(2),the production of H_(2) and CH_(4) is significantly promoted in the process of CO_(2) catalytic conversion,while Mo_(2) C and Cu coprecipitation can inhibit the production of H_(2) and promote the further conversion of CO_(2) to CH_(4).After four hours of illumination,its cumulative CH_(4) production reaches 76.1μmol/g,which is 5.6 times that of pure TiO_(2).Cu deposition can promote CO_(2) adsorption and inhibit water vapor adsorption,thereby reducing H_(2) generation.The co-deposition of Mo_(2) C and Cu can effectively reduce the bandgap width of TiO_(2),inhibit the recombination of photo generated electrons and hole pairs,and promote the separation and transfer of photogenerated charges on the catalyst surface,thereby improving its photocatalytic activity.
作者
李扬
蔚慧健
靳立军
杨赫
李德康
胡浩权
LI Yang;YU Huijian;JIN Lijun;YANG He;LI Dekang;HU Haoquan(Institute of Coal Chenical Engineering,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,China)
出处
《洁净煤技术》
CAS
CSCD
北大核心
2023年第5期56-67,共12页
Clean Coal Technology
基金
国家自然科学基金资助项目(22278066)。
关键词
光催化还原
二氧化碳
氧化钛
类贵金属
铜
photocatalytic reduction
carbon dioxide
titanium oxide
noble metal-like
copper
