Theoretical design principles of metal catalysts for selective ammonia oxidation from high throughput computation

Abstract

Selective catalytic oxidation of ammonia (NH3-SCO) is a ubiquitous process in exhaust aftertreatment, yet making catalysts with high reactivity and selectivity at low working temperatures remains great challenge, due to...

Rational ensemble design of alloy catalysts for selective ammonia oxidation based on machine learning

“…The situation agrees well with the theoretical study about linear relation for binding behaviours of N-and O-related species on pristine and high entropy alloys. 21,43,44 The fact also demonstrates the urgent need of principal component analysis (PCA) to reduce correlated features, and corresponding percentages of variance explained by selected components (explain-ed_variance_ratio) in PCA are shown in Fig. 5d.…”

“…2,9,12 Some alloy catalysts based on these metallic systems exhibit superior catalytic performance for NH 3 -SCO. [15][16][17][18][19][20][21] Therefore, Ag, Au, Cu, Ir, Pd, Pt, and Rh are selected as primary and secondary elements to construct different surface ensembles on low-index facets for simulating the surface local environments of alloy catalysts, as shown in Fig. 2.…”

“…The phenomenon also occurs for the binding energy of other intermediates, which imply different ensemble effects on the binding energy of surface intermediates. Considering that binding energies of N* species on pristine metallic catalysts are mainly located in the range of −6.00 to 0.00 eV and too strong binding is unfavorable for NH 3 -SCO, 21 systems with N* binding energy lower than −6.00 eV are not taken into account in the later study.…”

“…[18][19][20] Our theoretical study on various metallic catalysts has revealed the primary descriptors for NH 3 oxidation reactivity and selectivity and further guided the high-throughput screening of A 3 B 1 -type alloy catalysts. 21 Despite some exciting explorations and progress till now, there lacks an insight into the rational design of specic ensembles for NH 3 -SCO alloy catalysts, and therefore, further revealing inherent catalytic behaviours of local ensembles is the foundation of the rational design of superior alloy catalysts.…”

Promoting the effects of CuSO4 on N2 selectivity in selective catalytic oxidation of ammonia over Pt/TiO2 catalysts

“…Surface reducibility is a key factor for the activity of catalysts in the NH 3 -SCO reaction. 25,26 The H 2 -TPR was used to characterize the surface reducibility of the catalyst and the results are shown in Fig. 5.…”