Stabilized CO2 reforming of CH4 on modified Ni/Al2O3 catalysts via in-situ K2CO3-enabled dynamic coke elimination reaction

CO 2 dry reforming of methane (DRM) is one of the most promising routes for the large-scale utilization of greenhouse gases (CO 2 and CH 4 ). However, it is still of challenges to develop catalysts that are efficient and cheap but are of high resistivity in coke formation to maintain long-term stability. Herein, K 2 CO 3 was used as a promoter to enable dynamic coke elimination reaction over the Ni/Al 2 O 3 for CO 2 reforming of CH 4 . K 2 CO 3 -modified Ni/Al 2 O 3 catalysts were synthesized via a wet co-impregnation method and investigated for DRM. The 1.0 K-Ni/Al 2 O 3 exhibited the best stability in the test of 96 h on stream at 800 °C. It was found that coke resistance of K 2 CO 3 modified catalyst was significantly improved, as the coke formation on 1.0 K-Ni/Al 2 O 3 catalyst was only 1/3 of that on Ni/Al 2 O 3 catalyst after a long-term test. Characterization results showed that the growth of Ni particles was suppressed because the addition of K 2 CO 3 enhanced the interaction between Ni and Al 2 O 3 . Meanwhile, the addition of K 2 CO 3 raises the basicity of the catalysts, which enhances the adsorption of CO 2 on the surface and subsequently facilitates CO 2 dry reforming of CH 4 . In addition, the transient experiment reveals that K 2 CO 3 enables a dynamic coke elimination reaction (KCER) via enhancing the catalytic reaction of disordered carbon with CO 2 , which is considered as a promising low-cost approach to stabilize the performance of the Ni-based catalysts in DRM reaction.