具有稳定缺陷位的氮化碳非热等离子体合成氨催化剂  

Carbon nitride catalysts with stable vacancy sites for non-thermal plasma-assisted ammonia synthesis

作　　者：谭默姝 孙德清 叶成康 李昆霖 王帅 TAN Moshu;SUN Deqing;YE Chengkang;LI Kunlin;WANG Shuai(State Key Laboratory of Physical Chemistry of Solid Surfaces,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学化学化工学院,固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《厦门大学学报(自然科学版)》2025年第1期137-145,共9页Journal of Xiamen University:Natural Science

基　　金：国家重点研发计划(2021YFA1501104);国家自然科学基金(21922201)。

摘　　要：[目的]氨不仅是重要的基础化工原料,也是极具潜力的氢能载体.发展非热等离子体催化技术将为温和条件下实现高效合成氨储氢过程带来可能.[方法]本研究利用介质阻挡放电固定床反应器系统考察了在非热等离子体条件下不同氧化物、碳材料和氮化物的合成氨催化性能及金属离子掺杂影响,并通过反应动力学、谱学表征等手段研究催化作用机理.[结果]研究表明,氮化碳、氮化硼等氮化物比常见的氧化物、碳材料在非热等离子体合成氨反应中表现出更优异的催化活性,但它们因易被加氢分解而快速失活.通过引入少量的Ni^(2+)能够有效稳定氮化碳中的缺陷位,显著提升催化剂的稳定性,并使其保持高催化活性.机理研究揭示,氮化碳催化剂在非热等离子体合成氨反应中遵循类Mars-van Krevelen机理.其利用表面氮空位高效捕获N_(2)解离产生的N原子,进而提升合成氨效率.[结论]该类具有稳定缺陷位的氮化碳催化材料为开发高性能非热等离子体合成氨催化剂提供了新思路.[Objective]Ammonia(NH 3)not only serves as an essential feedstock in the modern chemical industry,but also holds promise as a hydrogen carrier for the future hydrogen economy.Industrial ammonia production form dinitrogen employs the energy-intensive Haber-Bosch process,which suffers from harsh temperature and pressure conditions.The emerging field of non-thermal plasma catalysis brings the possibility of activating inert chemical bonds under mild conditions,making it highly attractive for developing next-generation ammonia synthesis technologies.However,efficient heterogeneous catalysts suitable for the non-thermal plasma-assisted ammonia synthesis remain underexplored.[Methods]This study systemically investigated the catalytic performance of various oxides,carbon materials,and nitrides,as well as the impact of metal ion doping on these materials,in non-thermal plasma-assisted ammonia synthesis using a fixed-bed reactor equipped with a dielectric barrier discharge system.Catalyst structure was characterized using spectroscopic methods,such as X-ray diffraction,X-ray photoelectron spectroscopy,transmission electron microscopy,and ultraviolet-visible diffuse reflectance spectroscopy.Kinetic assessment was carried out to unveil the catalytic mechanism.[Results]The results showed that nitrides,such as g-C_(3)N_(4) and h-BN,exhibited superior catalytic activity in non-thermal plasma-assisted ammonia synthesis compared to commonly-applied oxides(i.e.,SiO_(2),CeO_(2),MgO,Al_(2)O_(3),MgAl_(2)O_(4),ZnTiO_(3))and carbon materials(i.e.,active carbon,graphite,carbon nanotubes).However,these nitrides deactivated rapidly due to fast hydrogenative decomposition under the non-thermal plasma conditions.The introduction of highly-dispersed Ni^(2+)effectively stabilized the vacancy sites of g-C_(3)N_(4) formed during the non-thermal plasma catalysis,as evidenced by spectroscopic characterizations.These Ni/g-C_(3)N_(4) catalysts,with an optimal Ni loading of 0.1%(by mass),resulted in a substantial enhancement in catalyst stability w

关 键 词：非热等离子体 合成氨 氮化碳 氮空位 Mars-van Krevelen机理 

分 类 号：O643.322[理学—物理化学]