The effect of support on surface Ni-V species arrangement and consequences for catalytic DME dry reforming reaction

[Display omitted] •V2O5 modified Ni/α-Al2O3/MgAl2O4 and Ni/Al2O3/CaAl2O4.•Porous catalyst with enhanced stability.•Structure-surface morphology-activity study.•DME DR highly structure-sensitive.•Clear relationship between intrinsic activity (TOF) and Ni0 average particle size. This paper discusses the effect of vanadium modification of nickel deposited on porous supports of α-Al2O3/MgAl2O4 and Al2O3/CaAl2O4 type. A series of V-promoted Ni-based catalysts on supports were obtained by impregnation technique. The catalysts were characterized by microscopic and spectroscopic techniques, and their activities were compared. Catalyst activity studies were carried out in the dry dimethyl ether reforming (DME DR) reaction in the kinetic regime in the temperature range of 573–973 K under normal pressure at a process gas composition of DME:CO2 molar ratio = 1:1. The relationship between the structure, surface morphology of the catalysts and activity in the DME DR reaction has been investigated. The DME DR reaction over V-modified N–catalysts was shown to be highly structure-sensitive, as confirmed by the clear relationship between intrinsic activity (TOF) and average particle size of metallic nickel (Ni0) particles. Due to the inherent specificity of the C–H (411 kJ/mol), C-C (346 kJ/mol), CH3-OCH3 (335 kJ/mol), and C–O (358 kJ/mol) bonds cleavage, the structure sensitivity was slightly higher than for methane reforming. In addition, the moderate basicity exhibited by α-Al2O3/MgAl2O4 type supported catalysts ensured the highest stability of the Ni and Ni-V active phase, with low methane selectivity above 623 K.