TY - JOUR

T1 - NO + H2 reaction over Pd(110)

T2 - TPD, TPR and DFT study

AU - Bryliakova, Anna A.

AU - Matveev, Andrey V.

AU - Tapilin, Vladimir M.

AU - Gorodetskii, Vladimir V.

PY - 2018/4/1

Y1 - 2018/4/1

N2 - Temperature-programming desorption (TPD) and temperature-programmed reaction (TPR) have been applied to study the reduction of 15NO by deuterium on a Pd(110) surface. TPR results show that the reaction occurs in the autocatalytic regime of surface explosion with the rate-limiting step of 15NOads dissociation into highly reactive Oads and 15Nads atoms. The steady-state reaction leads to formation of 15N2, D2O, 15ND3 and 15N2O products. The phenomena of a reaction rate hysteresis observed during a heating-cooling cycle can be attributed to accumulation of 15NOads at low temperatures followed by surface explosion at T ∼ 490 K. The binding energies and structural parameters of species involved in the NO + H2 reaction over Pd(110) have been calculated by the DFT technique, and plausible reaction pathways have been considered. NO dissociation from the most stable short bridge site (Eb = −1.94 eV) occurs via the intermediates in on-top and long bridge modes with lower binding energy (Eb = −1.31 to 1.65 eV). The energy of transition states reaches 0.2–0.26 eV over energy of NO in a gas phase, which confirms the rate-limiting role of NO dissociation. It has been demonstrated that OHads-group formation is the rate-limiting step of water molecule generation. Subsequent H2O formation occurs via disproportionation of the OHads intermediates.

AB - Temperature-programming desorption (TPD) and temperature-programmed reaction (TPR) have been applied to study the reduction of 15NO by deuterium on a Pd(110) surface. TPR results show that the reaction occurs in the autocatalytic regime of surface explosion with the rate-limiting step of 15NOads dissociation into highly reactive Oads and 15Nads atoms. The steady-state reaction leads to formation of 15N2, D2O, 15ND3 and 15N2O products. The phenomena of a reaction rate hysteresis observed during a heating-cooling cycle can be attributed to accumulation of 15NOads at low temperatures followed by surface explosion at T ∼ 490 K. The binding energies and structural parameters of species involved in the NO + H2 reaction over Pd(110) have been calculated by the DFT technique, and plausible reaction pathways have been considered. NO dissociation from the most stable short bridge site (Eb = −1.94 eV) occurs via the intermediates in on-top and long bridge modes with lower binding energy (Eb = −1.31 to 1.65 eV). The energy of transition states reaches 0.2–0.26 eV over energy of NO in a gas phase, which confirms the rate-limiting role of NO dissociation. It has been demonstrated that OHads-group formation is the rate-limiting step of water molecule generation. Subsequent H2O formation occurs via disproportionation of the OHads intermediates.

KW - DFT

KW - NO dissociation

KW - NO reduction

KW - Palladium

KW - Surface chemical reactions

KW - PD(110) SURFACE

KW - ELASTIC BAND METHOD

KW - DISSOCIATIVE ADSORPTION

KW - CO OXIDATION

KW - OSCILLATORY BEHAVIOR

KW - PD SURFACES

KW - MINIMUM ENERGY PATHS

KW - SADDLE-POINTS

KW - NITRIC-OXIDE

KW - DESORBING PRODUCTS

UR - http://www.scopus.com/inward/record.url?scp=85042407334&partnerID=8YFLogxK

U2 - 10.1016/j.mcat.2018.01.009

DO - 10.1016/j.mcat.2018.01.009

M3 - Article

AN - SCOPUS:85042407334

VL - 448

SP - 53

EP - 62

JO - Molecular Catalysis

JF - Molecular Catalysis

SN - 2468-8231

ER -