Optimization of Ni loading amount in Ni-CeZrO2 catalyst for dodecane steam reforming for the upcycling of plastic pyrolysis oil

In response to global efforts to address plastic pollution, pyrolysis of waste plastics offers a sustainable pathway for chemical recycling and clean hydrogen production. This study focuses on the steam reforming of dodecane, a key component of light oil derived from plastic pyrolysis, to produce hydrogen. Nickel-based catalysts supported on Ce 0.8 Zr 0.2 O 2 (Ni-CeZrO 2 ) with varying Ni loadings (1, 3, 5, and 10 wt%) were synthesized using a co-precipitation method and characterized by various characterization techniques. The catalytic performance was evaluated under steam reforming conditions at 750 °C. Among the prepared catalysts, 5 wt% Ni-CeZrO 2 exhibited the highest hydrogen yield and dodecane conversion due to its optimal balance of Ni 0 active sites, oxygen storage capacity, and strong metal-support interaction. The 10 wt% Ni-CeZrO 2 catalyst showed higher initial activity but suffered rapid deactivation due to excessive carbon formation, while lower Ni loadings (1 and 3 wt%) showed insufficient active sites for effective reforming. The results indicate that 5 wt% Ni-CeZrO 2 is the optimal loading amount for the steam reforming of dodecane, providing a balance between high activity and long-term stability. • Optimal Ni loading (5 wt%) enhances H 2 yield and dodecane conversion. • High OSC and SMSI of 5 % Ni reduce coke formation and boost catalyst stability. • Excess Ni (10 %) leads to rapid deactivation from amorphous carbon buildup. • Insufficient Ni (1 %, 3 %) lacks active sites, limiting reforming efficiency. • Ni-CeZrO 2 catalyst enables effective H 2 production from plastic pyrolysis oil.