Tailored active sites and pore structures: MOF-derived phosphorized carbon catalysts enhance levoglucosenone yield from amorphous cellulose pyrolysis

The selective pyrolysis of cellulose to levoglucosenone (LGO) remains challenging, primarily due to the lack of catalysts with tailored active sites and appropriate modification of cellulose microstructures, both critically determining reaction pathways and product selectivity. To realize the high-selectivity conversion of cellulose to LGO, this study synthesized metal-organic frameworks (MOFs) with tunable channel structures using ZIF-67 as the precursor, which were subsequently subjected to partial phosphidation to prepare MOF-derived phosphorized porous carbon (CoP/N-C) catalysts for the catalytic pyrolysis of amorphous cellulose (AMC). The effects of catalyst characteristics on the product distribution and LGO yield during AMC pyrolysis were systematically investigated using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and a lab-scale setup, while the catalytic pyrolysis mechanisms under the coupled effects of catalyst properties and reaction conditions were comprehensively elucidated. Results revealed that CoP/N-C significantly enhanced LGO yield from AMC pyrolysis. Particularly, the CoP (100) /N-C catalyst (synthesized with a Co:P ratio of 9:100) demonstrated optimal performance, achieving maximum LGO yields of 24.76 wt% in Py-GC/MS experiments and 18.89 wt% in lab-scale tests under optimized conditions (pyrolysis temperature: 320℃, catalyst:AMC ratio: 4:1). This study systematically revealed the structure-activity relationship between catalyst characteristics and LGO formation mechanisms, providing critical insights for further catalyst optimization and LGO yield enhancement.