(560dq) Research on Bifunctional Catalysts for Hydrogen Production from Dimethyl Ether Steam Reforming

Faced with the crisis of energy and environment, polymer electrolyte membrane fuel cells (PEMFCs) have a bright prospect on account of its characteristics. Currently, hydrogen supply is still one of the main obstructions of PEMFCs’ commercialization. Steam Reforming of Dimethyl Ether (SRDME) is a popular method in hydrogen production, and it can efficiently solve the hydrogen supply problems of PEMFCs. Current research revealed that two kinds of active sites are required in dimethyl ether steam reforming: one for the hydrolysis of dimethyl ether and one for steam reforming of methanol. Therefore, the study on bifunctional catalysts and the reaction mechanism are the most essential for the study of SRDME. Tranisition metal carbides (TMCs) have shown great promise for many important reactions such as methane dry reforming (DRM), water gas shift reaction (WGS), and steam reforming of dimethyl ether due to its noble-metal-like characteristics.

The new bifunctional catalyst Pt-MoC/Al₂O₃ was prepared for dimethyl ether steam reforming. Pt-MoC/Al₂O₃ exhibited a stable behavior and good performance on SRDME reaction. HRTEM results showed that Pt particles loaded on MoC surface uniformly. Pt particles had a strong interaction with MoC due to MoC’s capacity of dispersing and stabilizing metal particles. The performance test showed that conversion rate of dimethyl ether reached nearly 100% at 350℃, H₂ production rate and H₂ yield reached 1600 mmol·min^-1·g^-1 and 85% respectively. MoC had a strong ability to activate water at 350℃, and the O species produced by water could deactive MoC. SRDME reaction exhibited a stable behavior because of Pt-MoC/Al₂O₃ catalysts have the excellent resistance to oxygen posioning by coordinating the reactions in the SRDME reacting system.