Generation of Nano-Catalyst Particles by Spinodal Nano-Decomposition in Perovskite

TL;DR

This paper proposes a novel nano-catalyst generation mechanism via spinodal nano-decomposition in perovskite catalysts, supported by first-principles calculations, enabling design of precious-metal-free catalysts for automotive emissions.

Contribution

It introduces the spinodal nano-decomposition mechanism in perovskites for self-regenerating catalysts and demonstrates its potential for designing new materials without precious metals.

Findings

Spinodal region exists in La(Fe$_{1-x}$Pd$_x$)O$_3$ and La(Fe$_{1-x}$Rh$_x$)O$_3$.

Nano-particles form via spinodal decomposition within the host matrix.

Design of new catalysts without precious metals is feasible.

Abstract

A new mechanism of nano-catalyst generation based on the spinodal nano-decomposition in self-regenerating perovskite catalysts for automotive-emissions control is proposed. To demonstrate existence of the spinodal nano-decomposition in real perovskite catalysts, we performed first-principles calculations to evaluate the free energy of La(Fe$_{1-x}$Pd$_x$)O$_3$ and La(Fe$_{1-x}$Rh$_x$)O$_3$. The result indicates appearance of a spinodal region in the phase diagram of each material. Formation of nano-catalyst particles in the perovskite host matrix is crucial for the self-regeneration of perovskite catalyst. Based on the spinodal nano-decomposition model, possible materials are designed for new three-way catalyst with no contents of precious metal.