Adsorption and Reaction of Formic Acid on a Pseudomorphic Palladium Monolayer on Mo(110)
نویسنده
چکیده
The adsorption and reaction of formic acid, HCOOH, on monolayer and multilayer palladium supported on a Mo(110) surface have been studied using temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). On multilayer palladium, formic acid adsorbs molecularly at 100 K and desorbs primarily intact upon heating to 200 K. A small amount of the adsorbed formic acid in the first adsorbed layer undergoes decomposition to form CO, H2O, and H2. No other surface reaction intermediates were identified using HREELS. In contrast to multilayer palladium, monolayer palladium exhibits a higher reactivity toward the decomposition of formic acid to form a surface formate species, as verified with HREELS. However, monolayer palladium shows a relatively low reactivity toward formate decomposition. The formate species is stable on the surface up to 350 K and exhibits an activation energy and preexponential factor for decomposition of 125 kJ/mol and 4.7 × 1018, respectively. Increasing the Pd thickness to three layers restores the bulk Pd surface chemistry of formic acid.
منابع مشابه
Adsorption of CO on a pseudomorphic palladium monolayer on Mo(l l0)
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