Insight into the Reduction of NO by H<sub>2</sub> on the Stepped Pd(211) Surface

Ling, Lixia; Zhao, Zhongbei; Feng, Xue; Wang, Qiang; Wang, Qianqian; Zhang, Riguang; Li, Debao

doi:10.1021/acs.jpcc.7b05024

Cited by 17 publications

(18 citation statements)

References 87 publications

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“…[18,35] Moreover, computeraided design of catalysts owns the advantages of low cost, high efficiency, and short development cycle compared with that of experiments. [36] In recent years, computational highthroughput methods which can perform large-scale screening have significantly accelerated the search for catalysts. [37][38][39][40] For example, Nørskov and co-workers [40] performed highthroughput screenings for highly active catalysts for hydrogen evolution reaction (HER) among metal alloys, where the BiPt alloy are found to show improved HER performance compared with pure Pt.…”

Section: Doi: 101002/smtd201800376mentioning

confidence: 99%

A General Two‐Step Strategy–Based High‐Throughput Screening of Single Atom Catalysts for Nitrogen Fixation

et al. 2018

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Electrocatalytic or photocatalytic N2 reduction holds great promise for green and sustainable NH3 production under ambient conditions, where an efficient catalyst plays a crucial role but remains a long‐standing challenge. Here, a high‐throughput screening of catalysts for N2 reduction among (nitrogen‐doped) graphene‐supported single atom catalysts is performed based on a general two‐step strategy. 10 promising candidates with excellent performance are extracted from 540 systems. Most strikingly, a single W atom embedded in graphene with three C atom coordination (W1C3) exhibits the best performance with an extremely low onset potential of 0.25 V. This study not only provides a series of promising catalysts for N2 fixation, but also paves a new way for the rational design of catalysts for N2 fixation under ambient conditions.

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Section: Doi: 101002/smtd201800376mentioning

confidence: 99%

A General Two‐Step Strategy–Based High‐Throughput Screening of Single Atom Catalysts for Nitrogen Fixation

et al. 2018

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“…Theoretical investigations on Pd(211) surfaces show that NO* activates through H 2 -assisted pathways to form HNOH* at higher temperatures (>500 K), while at low temperatures, H 2 scavenges O* to create empty sites where NO* can then react via NO-assisted pathways to form ONNO* that decomposes into N 2 through N 2 O. 31 Theoretical investigations on Pt(100) and (111) surfaces suggest that at low coverage and low H 2 pressure, NO* activates directly, 22 consistent with surface science observations, 23 but H-assisted routes dominate when co-adsorbed NO is present. Mechanistic investigations employing maximum rate analyses suggest that the kinetically relevant step in covered Pt(111) surfaces involves N−O scission and that the removal of site-blocking intermediates, such as N* or O*, by H 2 is facile.…”

Section: Introductionmentioning

confidence: 99%

Mechanism and Effects of Coverage and Particle Morphology on Rh-Catalyzed NO–H₂ Reactions

2020

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Three-way catalysts, which typically include Rh, are used to treat automotive exhaust and reduce nitric oxide (NO) with a combination of CO and H2, although few kinetic and theoretical investigations have studied NO–H2 reactions on Rh. Here, we examine NO activation, which is believed to control the rate of NO reduction, through direct, NO-assisted, and H2-assisted dissociation pathways on NO*-covered Rh(111) surfaces and Rh nanoparticle models using density functional theory (DFT) and contrast these results with previously reported data on Pt(111) surfaces. Saturation coveragesdetermined by incrementally adsorbing NO*were determined to be 5/9 ML NO* on Pt(111), 6/9 ML on Rh(111), and 1.38 ML on a 201-atom Rh nanoparticle (∼2 nm). Free energies of activation and reaction were calculated by DFT for the pathways at these coverages and interpreted through maximum rate analyses over a wide range of NO and H2 pressures to predict NO activation mechanisms and kinetics. Rates are inhibited by NO at all relevant NO pressures and to similar extents on all catalyst models. On Pt(111) surfaces, NO is activated through NOH* formation and dissociation (to N* and OH*) at low H2 pressures (<0.5 bar) and through HNOH* (to HN* and OH*) at high H2 pressures (>0.5 bar), resulting in a shift in the H2 dependency from half order to first order. NO is activated through NOH* formation and dissociation on Rh(111) at all relevant H2 pressures, with all other pathways being >1000 times slower. NO activation occurs with similar rates through either NOH* or HNO* on Rh particles at 1.38 ML NO*, indicating that these high coverages can shift mechanistic preferences. Predicted NO consumption rates are half order in H2 on Rh particles and surfaces and are similar in magnitude to one another, despite shifts in the mechanism; these rates on Rh are 106 times slower than Pt, consistent with the prior reports that demonstrate that equal turnover rates for Pt at 60 °C occur for Rh at 200 °C. This work demonstrates that strong NO bonds activate through bimolecular (assisted) pathways and that particle models of catalysts enable high coverages of strongly bound species, which can then influence relative rates and mechanistic predictions.

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“…during the reaction, the catalysts (such as Pd(111), 9 Rh(221), 10 and Pt(100) 11 ) exhibit a higher product selectivity toward N 2 or N 2 O. However, if NH is the key intermediate on the surfaces (such as Pd(211) 12 and hydroxylated rutile TiO 2 (110) 59 ), NO can be easily reduced to NH 3 , thus the catalysts exhibit a high selectivity toward NH 3 . For the present studied systems, among the N-containing products, NH 3 formation is the least competitive due to the higher ratelimiting energy barrier, 1. where E ads refers to the adsorption energy of NO or H 2 and ΔS is the entropy change induced by gas adsorption.…”

Section: Methodsmentioning

confidence: 99%

“…Platinum-group-metal (PGMs) catalysts including Pt, Pd, and Rh are commonly used for NO x degradation (deNO x ) owing to their good performance and wide temperature windows. − However, the high cost and low thermal stability of PGMs severely restrict their practical applications. For this reason, the endeavors have focused on developing alternative low-cost catalysts for the effective NO x reduction, such as non-noble metal catalysts or alloys of the noble metals with cheaper metals.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of Nitric Oxide Reduction by Hydrogen on Ni(110) and Ir/Ni(110): First Principles and Microkinetic Modeling

et al. 2019

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The nitric oxide (NO) reduction by H2 on the pure Ni(110) and single-atom Ir-doped Ni(110) (Ir/Ni(110)) surfaces are investigated by density functional theory calculations coupled with microkinetic modeling. The stability of the single-atom alloy (SAA) Ir/Ni(110) in vacuum and under real conditions is considered. The results show that NO dissociation is very facile on the clean and H-predosed Ni(110) surface, and the dissociated N atoms is more likely to couple with the surface-adsorbed NO to produce N2O than with the N atom to form N2. However, the energy barrier for N2 formation is largely lowered by the doped Ir, whereas that for N2O formation is greatly increased. Thus, N2 is energetically preferentially formed on the Ir/Ni(110) surface. Microkinetic calculations further demonstrate that under ultrahigh-vacuum conditions, the selectivity toward N2O is 100% below 420 K and that toward N2 is over 80% above 460 K, in line with the experimental observation. In contrast, Ir/Ni(110) exhibits markedly improved selectivity toward N2 in a wide temperature range (>90% at 320 K and 100% at T ≥ 340 K). The present work shows that the SAA Ir/Ni(110) catalyst is very effective in promoting the reduction of NO into N2 while largely suppressing N2O formation.

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Insight into the Reduction of NO by H₂ on the Stepped Pd(211) Surface

Cited by 17 publications

References 87 publications

A General Two‐Step Strategy–Based High‐Throughput Screening of Single Atom Catalysts for Nitrogen Fixation

A General Two‐Step Strategy–Based High‐Throughput Screening of Single Atom Catalysts for Nitrogen Fixation

Mechanism and Effects of Coverage and Particle Morphology on Rh-Catalyzed NO–H₂ Reactions

Mechanism of Nitric Oxide Reduction by Hydrogen on Ni(110) and Ir/Ni(110): First Principles and Microkinetic Modeling

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Insight into the Reduction of NO by H2 on the Stepped Pd(211) Surface

Cited by 17 publications

References 87 publications

A General Two‐Step Strategy–Based High‐Throughput Screening of Single Atom Catalysts for Nitrogen Fixation

A General Two‐Step Strategy–Based High‐Throughput Screening of Single Atom Catalysts for Nitrogen Fixation

Mechanism and Effects of Coverage and Particle Morphology on Rh-Catalyzed NO–H2 Reactions

Mechanism of Nitric Oxide Reduction by Hydrogen on Ni(110) and Ir/Ni(110): First Principles and Microkinetic Modeling

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Insight into the Reduction of NO by H₂ on the Stepped Pd(211) Surface

Mechanism and Effects of Coverage and Particle Morphology on Rh-Catalyzed NO–H₂ Reactions