Enhanced aromatic hydrocarbon production from biomass-plastic co-hydropyrolysis over Ni/MOF-derived catalyst

Catalytic co-hydropyrolysis of biomass and plastics offers a sustainable route to producing key chemical intermediates. Thus, this study reports the thermolytic modification of a metal-organic framework (MOF) and evaluates its impact on the evolved gases composition from the co-hydropyrolysis of Chilean Oak (ChOak) and polyethylene (PE). The MOF-derived catalyst (Ni/C-Al 2 O 3 ) was prepared by pyrolysis of MIL-53(Al), followed by nickel impregnation (15 wt%). Catalytic samples were characterized using XRD, SEM-EDX, TEM, NH 3 -TPD, and N 2 physisorption. Crystallographic analyses revealed the formation of an alumina-carbonaceous matrix and metallic nickel nanoparticles (8.9 nm). This novel structure exhibited a mesoporous nature and increased weak and intermediate acid site density. The catalytic performance of these materials was assessed via analytical pyrolysis (Py-GC-MS), varying parameters such as temperature, H 2 pressure, plastic-type, catalyst type, and feed composition (catalyst/biomass/plastic ratios). The introduction of the catalysts reduced the presence of oxygenated compounds (15.4 %) and significantly increased the yields of aliphatic hydrocarbons (53.6 %) and aromatic hydrocarbons (22.5 %). Remarkably, the bifunctional catalyst achieved an aromatic hydrocarbon yield of 71.5 % (63.5 % monoaromatics) under specific conditions: 86 % catalyst weight, 550°C pyrolysis temperature, 150 psi hydrogen pressure, and an LDPE/ChOak ratio of 2:1. These findings reveal the potential of Ni 0 /MOF-derived catalysts in the synthesis of chemical platforms during the co-hydropyrolysis of biomass/plastic while unravelling the complex compounds dynamics that are critical for process scalability and a deeper understanding of reaction mechanisms. • MIL-53(Al) pyrolysis yields an alumino-carbonaceous matrix with enhanced catalytic properties. • Ni-supported carbo-alumina efficiently catalyzes vapour deoxygenation and aromatization during co-hydropyrolysis. • Temperature, hydrogen pressure, and biomass/plastic/catalyst ratios influenced product selectivity. • An outstanding 65.6 % of BTX selectivity was achieved under optimized conditions.