Catalytic upgrading of biogas exclusively to metgas (CO-2H2) through the combined steam and dry reforming over Sm2O3 promoted robust Ni nano-catalysts supported on boron nitride nanosheets

• 8Ni-8Sm 2 O 3 /BNNS exhibited excellent catalytic performance. • Sm 2 O 3 introduction improved the activation of CO 2 & H 2 O, and the carbon resistance. • The Ni NPs-BNNS interaction lead to anti-sintering performance. Robust Ni-based nanocatalysts supported on boron nitride nanosheets (BNNS), modified by Sm 2 O 3 , were synthesized via the co-impregnation and freeze-drying methods. The optimized 8Ni-8Sm 2 O 3 /BNNS catalysts demonstrated remarkable initial catalytic activity during the combined steam and dry reforming of biogas, achieving CH 4 and CO 2 conversions of 95 % and 46 %, respectively, and maintaining stable performance for 200 h. The introduction of Sm 2 O 3 improved the amount of moderately basic sites and enhanced the activation of oxygen-containing molecules including CO 2 and H 2 O, thereby promoting the formation of reactive oxygen species (e.g., O*, OH*) and effectively removing the coke precursors, significantly enhancing the carbon resistance. Moreover, the strong interaction between the small-sized Ni nanoparticles (NPs) and the BNNS support endowed the catalysts with excellent anti-sintering performance. The satisfactory catalytic performance of the 8Ni-8Sm 2 O 3 /BNNS catalysts can be attributed to the surface oxygen vacancies generated by Sm 2 O 3 , the moderately basic sites, and interaction between the highly dispersed Ni NPs and the BNNS support.