Surface phase transformation of <scp>ZrO<sub>2</sub></scp> in <scp>VO<sub><i>x</i></sub>/ZrO<sub>2</sub></scp> catalysts for boosting propane nonoxidative dehydrogenation
Bohan Feng, Yuechang Wei, Jing Xiong, Dong Li, Qian Lian, Yuanfeng Li, Dawei Han, Zhen Zhao, Jian Liu, Weiyu Song, Chunming Xu
Abstract
Abstract The nanocatalysts of VO x deposited on ZrO 2 supports with single monoclinic (ZrO 2 ‐M), tetragonal (ZrO 2 ‐T), and binary monoclinic‐tetragonal (ZrO 2 ‐MT) phase were synthesized. VO x /ZrO 2 ‐MT catalysts exhibit better performance during propane nonoxidative dehydrogenation than VO x /ZrO 2 ‐M and VO x /ZrO 2 ‐T catalysts. Among VO x /ZrO 2 ‐MT catalysts, the conversion and deactivation rate constant of VO x /ZrO 2 ‐M 31 T 69 catalyst is 35.2% and 0.22 h −1 , respectively. The promoting role of ZrO 2 ‐MT is revealed by experiments and theoretical calculations. The MT‐mixed phase structure in VO x /ZrO 2 ‐MT catalyst improves the structural properties and dispersion of VO x . The tetragonal‐monoclinic transformation on the ZrO 2 ‐MT surface facilitates VO x reduction and produces additional V 3+ active sites. The highly dispersed V 3+ sites on the ZrO 2 ‐MT surface accelerate CH bond breaking and boost the desorption of propylene, which is the key reason for enhancing activity and stability during the reaction, respectively. Insight into the role of surface phase transformation of ZrO 2 ‐MT is expected to obtain high‐efficient catalysts further.