Ni–Co bimetallic MgO-based catalysts for hydrogen production via steam reforming of acetic acid from bio-oil

• The Ni0.2Co0.8Mg6O7±δ catalyst performed better in both activity and stability in SR.
• A mixed oxide or solid solution of cubic phase Mg(Ni, Co)O formed after calcination.
• Stability of structure and electronic properties was found.
• Resistance to both oxidation of active metals and carbon deposition was observed.

Acetic acid (AC) is a representative compound of bio-oil via fast pyrolysis of biomass, and can be processed for hydrogen production via steam reforming (SR). In the current work, the NixCo1−xMg6O7±δ (x = 0–1) bimetallic catalysts were prepared via co-precipitation and impregnation, and tested in SR of AC. The reaction results indicate that the monometallic catalysts were deactivated obviously in SR, while the Ni0.2Co0.8Mg6O7±δ bimetallic catalyst performed better in both activity and stability: not only the conversion of AC remained stable near 100%, but also the H2 yield maintained stable near 3.1 mol-H2/mol-AC. The results of XRD, BET, XPS, TG and TEM indicate that the high catalytic performance of the Ni0.2Co0.8Mg6O7±δ catalyst can be attributed to 1) resistance to oxidation of active metals, 2) resistance to coking, and 3) stability of structure and electronic properties.