Experimental and Kinetic Modeling Study of Toluene Steam Reforming Over a Ni‐Rh/MgO Catalyst

ABSTRACT Toluene steam reforming (TSR) plays a vital role in hydrogen production and tar removal during biomass gasification, yet accurate kinetic representation remains challenging due to surface heterogeneity and complex adsorption‐reaction pathways. A bimetallic Ni‐Rh/MgO catalyst was synthesized via the sol‐gel method and thoroughly characterized using inductively coupled plasma optical emission spectroscopy (ICP‐OES), N 2 adsorption‐desorption, X‐ray diffraction (XRD), hydrogen temperature‐programmed reduction (H 2 ‐TPR), and CO 2 ‐temperature programmed desorption (TPD), thermogravimetric analysis (TGA), temperature‐programmed oxidation (TPO) and Raman spectroscopy analyses. Kinetic experiments were performed at 400°C–700°C and gas hour space velocity (GHSV) values of 6,000–9,000 h − 1 . Four kinetic models including power law, Langmuir–Hinshelwood (LH), Langmuir–Freundlich (LF), and Eley–Rideal were developed and statistically validated using mean absolute error (MAE), mean absolute relative error (MARE), and coefficient of determination ( R 2 ) metrics. Among the models, the LF formulation demonstrated the highest predictive accuracy ( R 2 = 0.995, MAE = 1.97, MARE = 6.12%) for both toluene conversion and H 2 selectivity. The LF model effectively captured heterogeneous adsorption and nonideal surface behavior, offering a physically meaningful interpretation of TSR kinetics. This work introduces, for the first time, a mechanistic LF kinetic framework for TSR over Ni‐Rh/MgO, bridging empirical and mechanistic approaches to provide realistic adsorption‐reaction descriptions. The proposed model delivers quantitative predictive capability for reactor‐scale modeling and catalyst optimization, contributing valuable insights for hydrogen production and toluene reforming applications.