Ni12P5被限制在半孔SiO2中,具有接近单位CO的选择性和对CO的增强催化活性2化
Shidong Bao1, Tao Liu2, Heyun Fu1
1State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
ACS applied materials & interfaces
|September 25, 2023
概括
化催化剂的化增强了二氧化碳对碳的化选择性,而不是CH4. 将Ni12P5纳米粒子限制在SiO2通道中,通过直接的CO2解离路径进一步提高了活性和CO选择性.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 通过逆水气转移 (RWGS) 反应的二氧化碳 (CO2) 化是二氧化碳利用的关键策略.
- 开发高活性和选择性的Ni基催化剂用于二氧化碳化仍然是一个重大挑战.
- 控制甲 (CH4) 和一氧化碳 (CO) 之间的产品选择性对于高效的二氧化碳转化至关重要.
研究的目的:
- 使用酸Ni催化剂,调整二氧化碳从CH4化到CO的产品选择性.
- 调查催化剂结构,特别是化物阶段和纳米粒子限制对催化性能的影响.
- 阐明反应机制和CO吸附物种在确定产品选择性的作用.
主要方法:
- 通过化修饰的SiO2支持的Ni催化剂的合成.
- 在半孔SiO2通道 (Ni12P5@SBA-15) 中制备封闭的Ni12P5纳米粒子.
- 在现场扩散反射的红外里埃变换光谱 (DRIFTS) 和密度函数理论 (DFT) 的计算.
主要成果:
- 化催化剂通过几何效应显著地将产品选择性从CH4转变为CO.
- 化催化剂 (Ni12P5和Ni2P) 的二氧化碳转化率不同,Ni12P5更活跃.
- 由于纳米粒子的限制,Ni12P5@SBA-15表现出增强的活性和近单位的CO选择性.
- 在化催化剂上的弱线性结合的CO有利于高的CO选择性,与Ni催化剂上的强多结合的CO形成鲜明对比.
结论:
- 化SiO2支持的Ni催化剂有效调整了CO2化对CO的选择性.
- 对于高活性和选择性而言,Ni12P5阶段和限制在中孔SiO2通道 (Ni12P5@SBA-15) 中至关重要.
- 该研究阐明了直接的二氧化碳解离路径,将吸附的二氧化碳作为关键中间体,强调了二氧化碳结合强度在确定产品选择性的重要性.
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