Catalytic performance of Cu-Ni-Al spinel for methanol steam reforming to hydrogen

Using copper hydroxide, nickel acetate and pseudoboehmite as materials, the Cu-Ni-Al spinel catalysts were synthesized by the solid-phase method. The effects of Cu/Ni/Al molar ratio and calcination temperature on specific surface area, phase composition, reduction performance and surface property of Cu-Ni-Al spinel catalysts were characterized by BET, XRD, H₂-TPR and XPS. Moreover, the sustained release catalytic performances of Cu-Ni-Al spinel samples for methanol steam reforming were tested. The obtained results indicated that with increasing the calcination temperature, the content of Cu-Ni-Al spinel increased, but the size of spinel particles increased and the specific surface area decreased. Change of the calcination temperature and Cu/Ni/Al molar ratio led to different specific surface area, reduction performance and surface property of Cu-Ni-Al spinel catalysts, thus showing different sustained release catalytic performance. Comparing with those of stoichiometric ratio of Cu/Al=1:2, spinel solid solutions with smaller particle size, higher specific surface area and pore volume, more hardly-reducible spinel and better sustained release catalytic performance were obtained with the nonstoichiometric ratio of Cu/Al=1:3. The results of catalyst evaluation indicated that active copper species were released from Cu-Ni-Al spinel lattice and thus took part in the catalytic action. Among the prepared catalysts, CNA3-1000 catalyst showed the highest catalytic activity and stability.