Highly active nano α-Fe2O3 catalyst prepared by PEG-assisted precipitation approach for the selective synthesis of o-cresol at low temperature

As a vital chemical intermediate, o-cresol is integral to many high-value manufacturing processes. Its synthesis via the methylation of phenol using methanol represents a green and atom-efficient route. Despite exhibiting promising ortho -selectivity, conventional α-Fe 2 O 3 catalyst are often limited by insufficient activity under mild conditions, restricting their practical utility. To address the limited catalytic efficiency of conventional α-Fe 2 O 3 in low-temperature o-cresol synthesis, a nano α-Fe 2 O 3 catalyst was fabricated using a polyethylene glycol (PEG) assisted precipitation method. The catalyst was comprehensively characterized using XRD, N 2 physisorption, TEM, NH 3 -TPD, XPS and EPR. These analyses elucidated the role of PEG in the catalyst synthesis, demonstrating that the PEG-assisted method significantly enhances specific surface area, acidity and oxygen vacancies, thereby collectively improving catalytic performance. Compared to α-Fe 2 O 3 , the novel catalyst achieved a significantly higher phenol conversion of 15.8 % versus 8.5 % under 340 °C and 3 h −1 . Furthermore, the amount of PEG added in the assisted precipitation process was optimized and the mechanism of the phenol methylation reaction over 2.5PEG/α-Fe 2 O 3 was clarified. The results provide a basis for designing efficient catalysts, thereby facilitating their industrial application in o-cresol production.