Au–Pd Tandem Photocatalysis for Nonoxidative Coupling of Methane toward Ethylene
Chengyun Tang, Shulin Du, Haowei Huang, Siyi Tan, Jiwu Zhao, Hongwen Zhang, Wenkang Ni, Xuanyu Yue, Zhengxin Ding, Zizhong Zhang, Rusheng Yuan, Wenxin Dai, Xianzhi Fu, Maarten B. J. Roeffaers, Jinlin Long
Abstract
Photocatalytic nonoxidative coupling of CH 4 to C 2 H 4 with a high rate and selectivity is considered challenging and impractical due to complex chemical pathways and unfavorable thermodynamics. This work introduces a strategy of tandem photocatalysis based on Au and Pd nanoparticles codeposited on a Bi 2 NbO 5 F photocatalyst, which divides the CH 4 to C 2 H 4 reaction into two distinct steps carried out in tandem by multiple activity components, i.e., CH 4 coupling to C 2 H 6 on Au and C 2 H 6 dehydrogenation on Pd. As a result, the optimized Au–Pd/Bi 2 NbO 5 F shows CH 4 coupling to C 2 H 4 with a high yield of 22.6 μmol g –1 h –1 and selectivity of 63% under simulated solar light irradiation. The reaction pathway is investigated by a series of activity experiments and in situ characterizations, demonstrating separate steps on Au and Pd. This work proposes a general strategy for the future design of photocatalysts to drive complex reactions efficiently and selectively based on the concept of a tandem system.