We report for the first time an investigation on the catalytic behavior of protonated clinoptilolite zeolite in propane-SCR-NOx. The protonated Iranian clinoptilolite zeolite shows a promising performance for NOx abatement via selective catalytic reduction by propane. Maximum activity (72% conversion of NOx to N-2) is achieved at 450 degrees C at a low GHSV of 20,280 h(-1). Size dependency of the nitrogen production reaction rate is insignificant for particle sizes equal or smaller than 500 mu m. A Hinshelwood-Langmuir type reaction mechanism has been proposed that predicts satisfactorily the NO2/NOx mixture conversion rate in the temperature range of 300-400 degrees C as a function of NO2 and NOx concentration and reaction temperature for an GHSV in the range of 27,000-30,400 h(-1). Kinetic analysis was performed based on the data obtained by an integral reactor system. The activation energy of the surface catalyzed reactions proposed has been calculated in the range of 43-51 kJ mol(-1). (C) 2013 Elsevier B.V. All rights reserved.