Behavior of S, SO, and SO₃ on Pt (001), (011), and (111) surfaces: A DFT study

In the hybrid sulfur (HyS) cycle, reaction between SO2 and H2O is manipulated to produce hydrogen with water sulfuric acid as by-products. However, poisoning of catalyst has been widely reported occur in this which due strong chemisorption on metal surface. The catalysts may deactivate a result these impurities present reactants or incorporated during its preparation operation HyS cycle. Here, we report density functional theory investigation interaction S, SO, SO3 Pt (001), (011), (111) surfaces. First, have investigated adsorption single gas phase molecules three During adsorption, 4F hollow sites (001) (011) surfaces fcc site surface were preferred. S followed trend (001)4F > (011)4F (111)fcc, while SO showed (011)bridge/4F (111)fcc was most stable S,O,O bound configuration sites. coverage increased all until monolayer obtained. highest for shows (001)S = (111)S (011)S, it (001)SO (011)SO (111)SO, similar where found (001)SO3 (011)SO3 (111)SO3. These trends indicate that more susceptible species poisoning. It also evident both reactive toward leading formation S2. high SO4, especially thermodynamics indicated an temperature up 2000 K resulted fully covered elemental S. θ ≥ 1.00 0.78 experimental region cycle operated. Lower coverages observed size molecule.