The focus of this work was the study of catalytic combustion over a flat plate, or fin, from which heat was extracted from the trailing edge of the fin. This enabled those factors that effect the heat transfer to the sink to be elucidated. Experimental work was conducted that involved passing a heated lean fuel (either carbon monoxide or propane) in air mixture over a catalytic fin. The temperatures along the fin and across the fluid boundary layer were measured. Experimental conditions varied were bulk gas (or foe stream) fuel concentration, coolant temperature, the temperature of the bulk gas and velocity of the bulk gas. A model of the fin was derived using the basic equations of momentum, energy and conservation of chemical species for boundary layer flow. The model equations were solved numerically using a combination of orthogonal collocation and finite difference techniques and theoretical predictions were compared with experimental results. Theoretical predictions of the fin and boundary layer temperature were, generally, in excellent agreement with experimental values. (C) 2000 Elsevier Science B.V. All rights reserved.