Two-stage fast pyrolysis and catalytic steam reforming of corn waste bio-oil for hydrogen production: Screening and optimization of Ni Fe catalysts supported on porous clay heterostructures

Converting agricultural residues into hydrogen offers a promising route toward low-carbon energy. This study presents a two-stage process combining fast pyrolysis of con waste bio-oil followed by catalytic steam reforming (CSR) using Ni Fe catalysts supported on porous clay heterostructures (PCH). Fast pyrolysis at 500 °C for 1 h produced 41.4 wt% bio-oil rich in lignin-derived phenolics. Catalyst screening during reforming at 800 °C identified 0.8Ni–0.2Fe/PCH as the optimal formulation, delivering 58.8% H 2 yield and 87.3% feedstock conversion with 7.2 mmol/g cat carbon deposition after 1 h. Relative to monometallic counterparts, Ni Fe synergy improved reforming performance while reducing carbon deposition by up to 38.9%. Under autothermal reforming (ATR), optimizing temperature (700–900 °C) and O 2 /C ratios (0.15–0.45) improved H 2 selectivity by balancing reforming and oxidation reactions. Importantly, the 0.8Ni–0.2Fe/PCH remained highly stable over 170 h, sustaining >80% H 2 yield and >90% conversion with minimal carbon deposition. Characterization (BET, SEM–EDX, XRD, FTIR) confirmed well-dispersed Ni Fe species anchored within the PCH framework, consistent with enhanced stability and resistance to carbon deposition. These results highlighted the Ni–Fe/PCH as efficient and promising catalyst platform for hydrogen production from corn waste bio-oil. • Green hydrogen was produced from corn waste via two-stage fast pyrolysis and catalytic reforming. • 0.8Ni–0.2Fe/PCH exhibited the highest H 2 reforming performance and conversion at 800 °C in both 1 and 18 h tests. • A higher Ni/Fe ratio enhanced Ni–Fe synergy, reducing carbon up to 38.9% compared with monometallic Ni or Fe. • Optimizing temperature (700–900 °C) and O 2 /C under ATR operation enhanced H 2 selectivity and reduced carbon deposition. • Long-term operation (170 h) at 800 °C and O 2 /C 0.30 maintained high H 2 yield/conversion with low carbon (∼1.2 mmol/g cat ).