A Cu–Pd single-atom alloy catalyst for highly efficient NO reduction

Abstract

Highly active and selective NO reduction was achieved at low temperatures using a minimum amount of noble metal Pd.

On the behaviour of structure-sensitive reactions on single atom and dilute alloy surfaces

“…The high activity of Cu-based SAAs toward numerous chemical reactions has been experimentally confirmed. 4,11,14 We determine that, among the Cu-based SAAs, Ni/Cu and Rh/Cu bimetallic alloys exhibit the lowest dissociation barriers. The most facile bond cleavage reactions are predicted to occur on Ni/Cu surfaces (Fig.…”

“…12 Accordingly, the work of Zhang et al 11 is a testament to the unique catalytic properties offered by isolated reactive atoms doped on less reactive host materials. 13 In addition, very recent studies by Furukawa and co-workers highlight that Pd/Cu SAA nanoparticles supported on Al 2 O 3 are exceptional catalysts for the catalytic NO reduction by CO. 14 The latter reaction is crucial for stripping out harmful gases from catalytic converters. 15 In particular, the authors demonstrated that on a Pd/Cu SAA catalyst, NO was fully converted to N 2 at low temperatures (e.g.…”

“…200°C) and, remarkably, this occurred without the formation of other undesired products such as N 2 O. 14 The extraordinary catalytic performance of SAAs is ascribed to the distinctive electronic structure of the isolated dopant atom amid the host metal atoms. Photoemission spectroscopy and density functional theory (DFT) show that, for a number of SAA surfaces, the d band of the doped atom is very narrow, resembling that of a gas phase metal atom.…”

Single-atom site catalysts for environmental catalysis

“…PGMs have been proven efficient catalysts for SCR of NO in the presence of reducing agents, such as CO, H2, NH3, and HC. However, proper SCR is still challenging as it requires the development of catalysts characterized by: (i) good low-temperature catalytic activity, (ii) minimum use of PGMs, and (iii) elevated N2 selectivity and low N2O production [118,119]. Nevertheless, the simultaneous resolution of these issues remains very difficult.…”

“…It is well known that the group IB metals (Au, Ag, and Cu) are very capable for reduction of NO, such as Cu-exchanged sieve. Thus, some studies have used Cu as an inert element to modify the electronic factors of Pd and yield Cu5Pd/Al2O3 SAA catalyst with a much higher NO conversion and N2 selectivity than Cu/Al2O3 and Pd/Al2O3 catalysts in the presence of O2 and O2 + C3H6 [119]. However, NO conversion declined with time since some active sites became occupied by CO and C3H6 oxidation.…”