A Composite Catalyst with a Lamellar Fe₃O₄/Pt/Fe₃O₄ Structure and Complementary Dual Catalytic Functions

Abstract

A composite catalyst with a lamellar Fe₃O₄/Pt/Fe₃O₄ structure has been prepared from an Al₆₇Pt₇Fe₂₆ (at.%) alloy by leaching with an aqueous 10 % NaOH solution. The lamellar Fe₃O₄/Pt/Fe₃O₄ phase exhibits significant catalytic performance as measured by activity and selectivity during the steam reforming of methanol $\left( {{\text{SRM}}:{\text{CH}}_{ 3} {\text{OH }} + {\text{ H}}_{ 2} {\text{O}} \to {\text{CO}}_{ 2} + {\text{ 3H}}_{ 2} } \right)$ superior to the catalytic performance of Pt obtained from Al₂Pt and a conventional impregnated Pt/Fe₃O₄ catalyst under the same reaction conditions. It is clear that the Pt and Fe₃O₄ were primarily responsible for the catalysis of the decomposition of methanol $\left( {{\text{DM}}:{\text{ CH}}_{ 3} {\text{OH}} \to {\text{CO }} + {\text{ 2H}}_{ 2} } \right)$ and the water gas shift reaction $\left( {{\text{WGSR}}:{\text{ CO }} + {\text{ H}}_{ 2} {\text{O}} \rightleftarrows {\text{CO}}_{ 2} + {\text{ H}}_{ 2} } \right)$, respectively. These two reactions work together in a complementary manner to facilitate the overall SRM reaction due to efficient the heat transfer characteristics of the lamellar Fe₃O₄/Pt/Fe₃O₄ structure. In this study, we demonstrate that a lamellar structure is available to couple two separate reactions to obtain a new catalytic function.

Graphical Abstract

In order to improve catalytic properties (stability, functionality), we combined with eutectic alloys and leaching treatment to obtain alternately binary phases with nano-architecture for catalytic materials.