Defect-stabilized nickel on beta zeolite as a promising catalyst for dry reforming of methane

Abstract

Four different Ni-containing beta zeolite (Ni-BEA) catalysts were synthesized and applied for dry reforming of methane (DRM). Nickel silicate Ni-BEA(I) was synthesized via the single-step interzeolite transformation of nickel silicate MWW (Ni-MWW(I)). Ni-BEA(II) was synthesized via the interzeolite transformation of borosilicate MWW (B-MWW) into B-BEA, followed by Ni implantation. Ni-BEA(III) was synthesized employing the reverse order of the aforementioned two-step process, i.e., the implantation of Ni in B-MWW and the interzeolite transformation into Ni-BEA(III). Ni-BEA(IV) was prepared via the incipient wetness impregnation of Ni on H-beta. Although the four Ni-BEA catalysts exhibited a *BEA-type structure, the chemical state of Ni and surface properties (the silanol defects) varied significantly with respect to the synthetic conditions. The stabilization of the metallic Ni clusters by the defect hydroxyls on *BEA was calculated via density functional theory. Further, Ni-BEA(I) and Ni-BEA(II) containing defect-stabilized Ni exhibited high catalytic activity and stability toward DRM.