Laser enhanced H2 chemisorption on Ni1 − yO catalysts for CO2 reduction

The H2 adsorption on Ni1 − yO (y is the bulk stoichiometry deviation) samples, obtained by Ni(OH)2 calcination at 450°C, 900°C and 1200°C, is investigated by the temperature programmed desorption (TPD) method. Two types of specific sites for H2 chemisorption are identified on the surface of the NiO450 sample. The H2 adsorptions are associated with surface excess oxygen (over equilibrium). The UV laser radiation strongly influences the H2 adsorption on the highly defective surface of the NiO450 sample (over equilibrium). The reactivity with hydrogen decreases as the stoichiometry rises (NiO900 and NiO1200 samples).