Harnessing strong metal\u2013support interactions via a reverse route

Peiwen Wu,Carter W Abney,Shi-Ze Yang,Yongqiang Cheng,Zihao Yan,Wenshuai Zhu,Ayyoub M Momen,Jisue Moon,Sheng Dai,Huiyuan Zhu,De-En Jiang,Zili Wu,Victor Fung,Huaming Li,Shuai Tan,Dong Su,Aditya Savara,Na Li

doi:10.1038/s41467-020-16674-y

Abstract

Engineering strong metal–support interactions (SMSI) is an effective strategy for tuning structures and performances of supported metal catalysts but induces poor exposure of active sites. Here, we demonstrate a strong metal–support interaction via a reverse route (SMSIR) by starting from the final morphology of SMSI (fully-encapsulated core–shell structure) to obtain the intermediate state with desirable exposure of metal sites. Using core–shell nanoparticles (NPs) as a building block, the Pd–FeOx NPs are transformed into a porous yolk–shell structure along with the formation of SMSIR upon treatment under a reductive atmosphere. The final structure, denoted as Pd–Fe3O4–H, exhibits excellent catalytic performance in semi-hydrogenation of acetylene with 100% conversion and 85.1% selectivity to ethylene at 80 °C. Detailed electron microscopic and spectroscopic experiments coupled with computational modeling demonstrate that the compelling performance stems from the SMSIR, favoring the formation of surface hydrogen on Pd instead of hydride.

Highlights

Engineering strong metal–support interactions (SMSI) is an effective strategy for tuning structures and performances of supported metal catalysts but induces poor exposure of active sites
The core–shell Pd–FeOx NPs were obtained by a seed-mediated growth method with the pre-made Pd NPs as the seeds and iron (III) acetylacetonate, as the iron precursor that nucleated on Pd surface, forming an iron oxide shell
The strong metal–support interaction via a reverse route (SMSIR) was constructed by treating the Pd–FeOx NPs at 300 °C in a gas mixture of H2 and argon (Ar; 4 vol.% of H2), and the sample was named as Pd–Fe3O4–H

Summary

Introduction

Engineering strong metal–support interactions (SMSI) is an effective strategy for tuning structures and performances of supported metal catalysts but induces poor exposure of active sites. The formation of intermetallic structure of the supported metal and metal cations in the supporting oxide was observed[20,21] Despite these fascinating interfacial properties in SMSI, the formation of SMSI is restricted to specific combinations of elements, i.e., group VIII metals with high surface energy and transition metal oxides with low surface energy. Xiao et al reported a wet chemistry approach to construct SMSI in aqueous solution at room temperature, which was realized by engineering redox interactions between metals and supports This strategy was applicable to Au, Pt, Pd, and Rh Zhang et al engineered the SMSI between Au NPs and hydroxyapatite by treating the Au NP–hydroxyapatite composite in the air at high temperatures[17]

Methods

Results

Conclusion