Temperature-dependent highly active LaCaMgAl2O4 catalyst effect on carbon nanomaterial and hydrogen generation from polymethyl methacrylate plastic

Abstract

The increasing accumulation of waste polymethyl methacrylate (PMMA) plastics presents a significant environmental challenge, while the demand for renewable energy sources continues to rise. Thermochemical recycling is a prospective technique for converting waste plastics into high-value chemicals, both economically and environmentally. In this work, the catalytic pyrolysis of waste PMMA plastics over LaCaMgAl2O4 nanosheets (NSs) catalyst is being investigated for its potential to produce hydrogen and carbon nanotubes (CNTs) in a two-stage fixed-bed reactor. The yield and purity of the gaseous products, as well as carbon deposition, concerning the effects of temperature during the catalysis process. Additionally, a small portion of LaCa was incorporated into the MgAl2O4 composite in the pre-catalysts under investigation. Analyzing the physicochemical properties of the carbon nanomaterials that form provides valuable insights into the workings of different catalysts. It's noteworthy that LaCaMgAl2O4 NSs showed such large yields of H2 (82.71 vol% H2) and CNTs (388 mg g−1) at 750 °C. The LaCaMgAl2O4 NSs catalyst's impressive ability to produce CNTs and H2 gas at high yields underscores its efficacy and potential for real-world catalytic pyrolysis applications. This study emphasizes the Nanocatalyst's potential for large-scale catalytic pyrolysis operations, providing a workable and efficient way of converting waste plastics into high-value products and renewable energy.