Surface-nitrogen removal in a steady-state NO + H2 reaction on Pd(110).
Surface-nitrogen removal steps were analyzed in the course of a catalyzed NO + H(2) reaction on Pd(110) by angle-resolved mass spectroscopy combined with cross-correlation time-of-flight techniques. Four removal steps, i.e., (i) the associative process of nitrogen atoms, 2N(a) --> N(2)(g), (ii) the decomposition of the intermediate, NO(a) + N(a) --> N(2)O(a) --> N(2)(g) + O(a), (iii) its desorption, N(2)O(a) --> N(2)O(g), and (iv) the desorption as ammonia, N(a) + 3H(a) --> NH(3)(g), are operative in a comparable order. Above 600 K, process (i) is predominant, whereas the others largely contribute below 600 K. Process (iv) becomes significant at H(2) pressures above a critical value, about half the NO pressure. Hydrogen was a stronger reagent than CO toward NO reduction and relatively enhanced the N(a) associative process.
Ma
Yunsheng
Y
Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan.
Matsushima
Tatsuo
T
D000535:Aluminum / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D009569:Nitric Oxide / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D012680:Sensitivity and Specificity; D013499:Surface Properties; D013696:Temperature
D009569:Nitric Oxide; D010165:Palladium; D003300:Copper; D006859:Hydrogen; D000535:Aluminum; D009584:Nitrogen