Enhanced metal-promoter interaction over Na modified Co2C nanoprisms for high-efficiency hydrogen production from methanol steam reforming

As an important application for methanol-based energy-storage systems, methanol steam reforming (MSR) using appropriate catalysts can provide clean hydrogen via onboard production for fuel cells. However, owing to their unsatisfactory activity and stability, the use of the most common catalysts, including Cu-based and groups 8---10 transition metals, remains challenging. Herein, a series of Na-promoted Co2C nanoprism catalysts con-taining different Na loadings was used for the first time in MSR. The 1Na/Co2C catalyst showed an excellent activity and stability for MSR, with H2 production rates as high as 4637.9 & mu;mol/gcat/min at 250 degrees C, which outperforms most of the reported catalysts. In-depth characterizations revealed that a strong interaction between Na and Co2C stabilized the catalyst and promoted the dissociation of CH3OH and H2O. A further investigation of the reaction mechanism revealed that the reaction proceeded via the dehydrogenation of methanol and sequential water-gas shift reactions. Density functional theory calculations revealed that the Co2C (1 01) surface exhibited the lowest energy barrier and that the methoxy dehydrogenation was the rate-determining step. This work provides further valuable insights into the rational design of transition-metal carbide catalysts for MSR.

Automated summary

This study investigates the use of Na-promoted Co2C nanoprism catalysts with different Na loadings in methanol steam reforming (MSR). The 1Na/Co2C catalyst demonstrates excellent activity and stability, with H2 production rates higher than most reported catalysts. The strong interaction between Na and Co2C stabilizes the catalyst and promotes the dissociation of CH3OH and H2O. DFT calculations reveal that the Co2C (1 01) surface has the lowest energy barrier, and the dehydrogenation of methoxy is the rate-determining step. This work provides valuable insights into the rational design of transition-metal carbide catalysts for MSR.