Development of a multi-layered micro-reactor coated with Pt–Co/Al2O3 catalyst for preferential oxidation of CO

Pt–Co/Al2O3 catalysts were prepared with different Co/Pt weight ratios (0.3–1.8) and their performances for preferential oxidation of CO (PROX) were tested. The activity of the catalyst increased with Co/Pt weight ratio due to the increase of the area of active phase by interaction between Pt and Co species. The 13-layered micro-channel reactor was prepared by stacking the plates coated with Pt–Co/Al2O3 catalyst. The reactor was divided into three parts (inlet, middle, and outlet) to evaluate the performance of each part. Most of O2 supplied was depleted at the inlet part and the temperature gradient of the reactor occurred due to the high exothermicity of oxidations of CO and hydrogen. In order to prevent hot spot and temperature gradient, the reactor with non-uniform distribution of the catalyst (partially coating the catalyst on the channels) was prepared. The prepared reactor showed uniform temperature distribution and exhibited excellent performance for PROX.