Electro- and thermal-catalysis by layered, first series Ruddlesden-Popper oxides

•Review of catalysis/electrocatalysis by first series Ruddlesden-Popper oxides.•Effect of the A and B site composition on the catalytic properties of R-P-1 oxides.•Synthesis plays an important role in the electrocatalytic/catalytic properties.•Potential of R-P-1 oxides for thermal catalysis has not been fully explored.

First series Ruddlesden-Popper oxides (referred herein as R-P-1, with a formula An+1BnO3n+1 where n = 1) have been used in a number of electrochemical and thermochemical reactions. In this review, we examine in detail the effect of the synthesis methods and the composition of the A and B sites on their electrocatalytic/catalytic activity. Effects on important activity parameters, such as surface exchange coefficient (k), oxygen diffusion coefficient (D), hyperstoichiometry (δ), and electronic conductivity are discussed. We find that synthesis plays an important role in their final structure and hyperstoichiometric oxygen content, which significantly impact their activity. In addition, we show that the composition of the A and B sites has an effect on the catalytic/electrocatalytic activity parameters, such as D, k, δ, and electrical conductivity. The use of these oxides for thermal-catalysis is also discussed. We find that while R-P-1 oxides have been widely implemented for high temperature electrocatalysis, their potential for thermal-catalysis has not been fully explored. Limited reports on thermal-catalysis suggest that the redox properties of the B-site transition metal in these oxides, as well as the oxide’s ability to accept and release oxygen under reaction conditions play an important role in their catalytic activity. A perspective on catalysis by R-P-1 oxides is provided at the end of the review.

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