The controlled disassembly of mesostructured perovskites as an avenue to fabricating high performance nanohybrid catalysts

Yuan Wang,Hongxing Dai,Sean C Smith,Jason Scott,Andrew L Rohl,Julian D Gale,Hassan A Tahini,Xin Tan,Rose Amal,Hamidreza Arandiyan

doi:10.1038/ncomms15553

Yuan Wang, Hongxing Dai + Show 8 more

Open Access

https://doi.org/10.1038/ncomms15553

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Abstract

Versatile superstructures composed of nanoparticles have recently been prepared using various disassembly methods. However, little information is known on how the structural disassembly influences the catalytic performance of the materials. Here we show how the disassembly of an ordered porous La0.6Sr0.4MnO3 perovskite array, to give hexapod mesostructured nanoparticles, exposes a new crystal facet which is more active for catalytic methane combustion. On fragmenting three-dimensionally ordered macroporous (3DOM) structures in a controlled manner, via a process that has been likened to retrosynthesis, hexapod-shaped building blocks can be harvested which possess a mesostructured architecture. The hexapod-shaped perovskite catalyst exhibits excellent low temperature methane oxidation activity (T90%=438 °C; reaction rate=4.84 × 10−7 mol m−2 s−1). First principle calculations suggest the fractures, which occur at weak joints within the 3DOM architecture, afford a large area of (001) surface that displays a reduced energy barrier for hydrogen abstraction, thereby facilitating methane oxidation.

Highlights

Versatile superstructures composed of nanoparticles have recently been prepared using various disassembly methods
The findings reported by Fukino et al.[7] opened the door to many attractive new possibilities with the approach suggesting a new protocol towards mixed crystal nanoparticle synthesis
We implement a rational fragmentation strategy involving a 3DOM architecture as the precursor material, which is disassembled into well-defined structural building units to produce a mesostructured LSMO perovskite catalyst

Summary

Introduction

Versatile superstructures composed of nanoparticles have recently been prepared using various disassembly methods. We show how the disassembly of an ordered porous La0.6Sr0.4MnO3 perovskite array, to give hexapod mesostructured nanoparticles, exposes a new crystal facet which is more active for catalytic methane combustion. The hexapod-shaped perovskite catalyst exhibits excellent low temperature methane oxidation activity (T90% 1⁄4 438 °C; reaction rate 1⁄4 4.84 Â 10 À 7 mol m À 2 s À 1). We implement a rational fragmentation strategy involving a 3DOM architecture as the precursor material, which is disassembled into well-defined structural building units to produce a mesostructured LSMO perovskite catalyst. The surface chemistry and structure of the hexapod perovskite particles were examined by X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) computational studies so as to understand the origin of the enhanced methane oxidation activity exhibited by the 3D-hm LSMO

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