AbstractExtensive kinetic data for the methanation reaction over a Ni/Al2O3catalyst were obtained in a specially designed gradientless reactor operating at steady state. The reactor pressure was 101.3 kPa, and three temperatures were used, namely, 503, 513 and 523 K. The following three‐parameter phenomenological model based on a proposed Langmuir‐Hinshelwood mechanism adequately describes the data:r= L2K3K40.5k5P0.5H2Pco/ [1 +K3(k5/k6)Pco +K40.5P0.5H2]2With dissociative adsorption of hydrogen and hydrogen‐assisted dissociation of adsorbed carbon monoxide, the postulated mari is the CH surface group, and the rds is the hydrogenation of the surface CH