Catalytic pyrolysis of cellulose for producing phenols with porous carbon catalyst

Catalytic pyrolysis for the targeted production of renewable phenol—which serves as a crucial oxygenated fuel additive for upgrading bio-oil stability and a key platform chemical in modern biorefineries—represents a vital pathway for advanced biomass valorization. Yet, the rapid deactivation of catalysts remains a critical bottleneck hindering its industrial bioenergy application. This study employs phosphoric acid-activated carbon (P-AC) as a solid acid catalyst to systematically explore the process conditions and multi-dimensional deactivation mechanism of phenol production from cellulose pyrolysis, with optimal phenol selectivity achieved at 500 °C and a catalyst-to-feedstock mass ratio of 1.0. Catalyst deactivation arises from the synergy of physical pore blockage and chemical degradation: physically, coke deposition acts as non-selective “blanketing” of pore channels, inducing proportional and systemic degradation of the entire pore structure; chemically, TPD and XPS correlative analyses confirm that medium-strong acid sites composed of C-O-PO3 and C-PO3 functional groups are critical to catalytic performance, and their loss not only blocks the main phenol formation pathway but also triggers the reoccurrence of upstream intermediates (e.g., ketones, furans) and activates downstream side reactions forming pyrans and esters, ultimately resulting in systemic deterioration of the entire catalytic reaction network. This work provides novel theoretical insights into understanding the complex deactivation behavior of carbon-based catalysts and designing targeted regeneration strategies.