Sustainable coke-resistant Ca-Al nano-sized catalyst for cogenerating hydrogen and high-value liquid fuels via pyrolysis catalytic steam reforming reaction of the polystyrene-phenol mixture

Abstract

The production of synthetic plastics, particularly polystyrene (PS), has had a significant impact on humanity and has led to an increase in global waste. Since conventional treatment methods cannot effectively recycle these materials, this study aimed to find a solution by valorizing polystyrene waste and phenol through an in-situ pyrolysis-catalytic steam reforming reaction utilizing the γ-Al2O3 (Al) and CaO (Ca) nanomaterials for the production of hydrogen and liquid fuel. The catalysts were prepared using impregnation and hydrothermal techniques, and their physicochemical properties were characterized after being calcined and utilized. Among the catalysts used, the 2Ca3Al nanocatalyst had high performance due to its high surface area, uniformly distributed Ca and Al alloy, surface hydroxyl groups, and oxygen vacancies. At 700 oC, the 2Ca3Al nanocatalyst demonstrated a phenol conversion rate and H2 yield of 98.5 % and 92.5 %, respectively. The main compounds detected in the liquid product were tert-Butyl Hydroperoxide (TBH) and Dixanthogen.