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

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 S BET 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.

Graphene-Encapsulated Transition Metal@N/C Catalysts for Catalytic Copyrolysis of Biomass and Waste Plastics: Production of Linear α-Olefins and Aromatics

“…The Mn catalyst posted the strongest impeding synergy for aldehyde formation (−90.91%) for the 50:50 feed ratios. These observations indicated that the catalysts promoted deoxygenation reactions via demethoxylation, decarbonylation, dehydration, and decarboxylation routes. ,, However, for alcohol formations, all of the catalysts showed positive promotion synergy parameters and Zn-modified catalysts displayed the highest value (>175%), followed by Ni-catalysts (>80%) for all feed ratios. The increased promotion of alcohol formation may be attributed to reactions between the abstracted hydroxyl radical from the WS biomass and the alkyl radicals formed from the cracking of HDPE. ,, The synergistic parameter study results showed that the no-cat and catalytic copyrolysis process enhanced the synergy between WS and HDPE for producing valuable aromatic and α-olefin hydrocarbons and reduced the formation of oxygenates significantly.…”

“…Estimated Synergy Parameters for Copyrolysis Product Components indicated that the catalysts promoted deoxygenation reactions via demethoxylation, decarbonylation, dehydration, and decarboxylation routes. 6,14,19 However, for alcohol formations, all of the catalysts showed positive promotion synergy parameters and Zn-modified catalysts displayed the highest value (>175%), followed by Ni-catalysts (>80%) for all feed ratios. increased promotion of alcohol formation may be attributed to reactions between the abstracted hydroxyl radical from the WS biomass and the alkyl radicals formed from the cracking of HDPE.…”

“…The pyrolysis process has garnered significant attention from researchers due to its simplicity and feed-agnostic properties. , However, standalone biomass pyrolysis yields low-quality fuel characterized by a high water content, low calorific value, high viscosity, and acidity, rendering it unsuitable for direct use in existing fuel processing systems. To enhance the quality of bio-oil and generate useful aromatics and olefins as petrochemical feedstock, − various catalysts have been explored for biomass pyrolysis. Yet, the catalytic pyrolysis of biomass alone is still hindered by rapid catalyst deactivation due to coking and insufficient yields of useful chemicals.…”