Microwave-Induced One-Pot Preparation of Bifunctional N-Fe/BC Catalysts and Oriented Production of Phenol-Enriched Bio-Oil from Biomass Pyrolysis: Catalyst Synthesis, Performance Evaluation, and Mechanism Insight via Theoretical Calculations
Juan Luo, Guojin Gong, Chongwei Cui, Shichang Sun, Junhao Lin, Rui Ma, Jiaman Sun
Abstract
To recover valuable products from biomass, bifunctional catalysts (N-Fe/BC) capable of microwave absorption and oriented production of phenolics were prepared by a one-pot method involving the microwave-induced K2FeO4. Its catalytic performances were evaluated, and the catalytic mechanism was explored using a model compound and DFT calculations. The cycle performance and deactivation mechanism were investigated. N-Fe/BC possessed a large SBET value (265.21 m2 g–1), good pore distribution, and abundant Fe and N species, resulting in good dielectric and catalytic properties. After catalysis, the heating rates reached 63.78–107.84 °C min–1, and the selectivity and yield of phenol-enriched bio-oil improved significantly, reaching maximum values of 80.28% and 38.09 wt % at 550 °C with 20 wt % N-Fe/BC, respectively. Model compound experiments and DFT calculations showed that N-Fe/BC directionally generated phenolics by changing the reaction path and forming “hot spots” that stimulated the catalytic reforming of oxygen-containing compounds. The catalytic performance decreased slightly after five cycles, due to active site loss, carbon deposition, and pore collapse.