Boosting hydrogen production from steam reforming of glycerol via constructing moderate metal-support interaction in Ni@Al2O3 catalyst

• Regulatory mechanism of nickel-alumina interaction on catalytic activity was elaborated. • Ni@Al 2 O 3 with moderate nickel-alumina interaction exposed high active nickel surface areas. • Ni@Al 2 O 3 with moderate nickel-alumina interaction achieved superior catalytic performance. • Nickel-alumina interaction can affect the morphology and growth mechanism of coke deposition. In this manuscript, the relationship between metal-support interaction and the catalytic performance for hydrogen production from steam reforming of glycerol (GSR) over Ni-Al 2 O 3 based catalysts was studied. Pure core–shell structured Ni@Al 2 O 3 and supported Ni/Al 2 O 3 with a fixed medium-sized nickel particle were synthesized without the other additional components to eliminate the influence of other factors. And then the nickel-alumina interaction of Ni@Al 2 O 3 was tuned precisely and the regulatory mechanism of nickel-alumina interaction on catalytic activity was elaborated. The strong nickel-alumina interaction over Ni/Al 2 O 3 and Ni@Al 2 O 3 with high calcination temperature resulted in the formation of NiAl 2 O 4 , which was unfavorable to the reduction of nickel species to obtain the more active nickel. Consequently, the poor catalytic performance was caused. The moderate nickel-alumina interaction of Ni@Al 2 O 3 promoted the exposure of the maximum area of active nickel and obtained higher turnover frequency (TOF). Thus, Ni@Al 2 O 3 showed the high catalytic performance in GSR. Additionally, metal-support interaction affected the morphology and growth mechanism of coke deposition. For Ni@Al 2 O 3 with moderate nickel-alumina interaction, the formation of carbon deposition followed the ‘tip-growth’ pattern, and the filamentous coke was mainly formed on catalysts. Conversely, ‘base-growth’ pattern was followed on Ni/Al 2 O 3 with strong nickel-alumina interaction to form mainly encapsulated coke. The research findings of the regulatory role of interaction between nickel and alumina on catalytic performance will provide valuable guidelines for designing effective GSR catalysts.