Origin of hydrogen in aromatic and olefin products derived from (Al-) MCM-41 catalysed co-pyrolysis of glucose and polypropylene via isotopic labelling

Abstract Catalytic co-pyrolysis of biomass and plastic is an effective method to improve bio-oil produced by biomass pyrolysis. To further exploit the synergistic mechanism between biomass and plastic, co-pyrolysis of polypropylene (PP) and deuterated glucose (G) (1:1 wt%) over mesoporous catalysts MCM-41 (M) and Al-MCM-41(Al) was studied using a thermal gravimetric analyser (TGA) and pyrolysis–gas chromatography–mass spectrometry. The findings show that M and Al overlap the decomposition of PP and G, making synergy possible. With catalysts M and Al, the yield of olefins increases sharply to 36.75% and 13.66% more than the calculated value. Additionally, hydrogen transfers from G to 4C–13C olefins and aromatic products are influenced by the catalysts. Without a catalyst, there is no deuterium in all the co-pyrolytic products. However, catalysts M and Al can help transfer one to four deuterium atoms from G to the products. M and Al provide the pool for the intermediates of PP and G to form synergetic products. Additionally, Al helps break the carbon chain and transfer more deuterium into the products by reducing carbon atoms.