载体酸位对Pt/Al2O3催化剂积碳形成过程的影响

Pt-based catalyst is one of the commercial catalysts for propane dehydrogenation, which suffers from catalytic deactivation and unstable catalytic stability. Herein, it is of great importance to investigate Pt catalyst with high catalytic activity and stability.This work described an investigation regarding the influence of acid site of support on coke formation.The high-temperature steam treatment can alter the amount of acid sites, while bringing negligible change to active metal sites since the catalytic performance as well as metal dispersion remained unchanged. The change in the amount of acid sites influences the ratio of coke that deposited on metal surface and supports. Through NH3-TPD and TPO experimental analysis, the mechanism of coke formation is believed that the coke precursor is first formed on metal surface via condensation and polymerization of propylene and then transferred to the support, followed by further dehydrogenation and condensation, which eventually forms the type of coke that have higher C/H ratio and oxidation temperature.