Sequential catalysis enables efficient pyrolysis of food waste for syngas production.

Thermochemical conversion technologies are emerging as one of the most promising approaches to tackle food waste crisis. However, the existing techniques confront significant challenges in terms of syngas selectivity and catalyst stability. This study introduced a cost-effective Joule heating approach utilizing sequential catalysts composed of treated stainless steel (SS) and biochar to optimize syngas production from food waste. This system achieved a syngas yield of 17.64 mmol⋅g, marking a 76.40 % improvement over conventional thermal pyrolysis. The molar ratio of hydrogen (H) to carbon monoxide (CO) was adjustable from 0.36 to 0.94, offering flexibility for different applications. Over five cycles, the system maintained robust catalytic stability, with only a 9.70 % decrease in syngas yield. Furthermore, the sequential catalysts proved versatile across diverse food wastes, achieving a maximum selectivity of 87.99 vol%. This approach enhanced catalyst activity and stability by promoting the sequential cracking of large oxygenates and reforming small molecules.