The coverage-dependent sticking probabilities of molecular hydrogen on polycrystalline copper supported on alumina have been determined in the temperature range 213-273 K by analysis of the hydrogen frontal adsorption line shape. In this temperature range the initial sticking probabilities increase from 8x 10(-13) (213 K) to 1.3x 10(-10) (273 K). The overall activation energy to adsorption has been found to be 42 kJ mol(-1). The application of reactive frontal chromatography for the measurement of hydrogen sticking probabilities on copper is a novel variant of the N2O reactive frontal chromatographic method, developed for the measurement of copper surface areas. Its use here shows that reactive frontal chromatography may be applied generally to any adsorbate/adsorbent system involving activated adsorption and low sticking probabilities.