Degree Type

Dissertation

Date of Award

2019

Degree Name

Doctor of Philosophy

Department

Chemical and Biological Engineering

Major

Chemical Engineering

First Advisor

Yue Wu

Abstract

Tuning catalytic active sites through metal-support interactions (MSIs) has emerged as an effective strategy to design supported metal catalysts. The development and selection of supports are paramount for achieving the desired catalytic performance, which are however, great challenges. This dissertation involves elucidating the MSIs between platinum and two-dimensional early transition metal carbides (MXenes) and harnessing the MSIs for several industrial catalytic processes and electrocatalytic reactions.

This work discovered the reactive metal support interactions (RMSI) in MXenes supported Pt catalysts. RMSI refers to a chemical reaction between a metal and the support that induces the formation of bimetallic structures. By utilizing atomic resolution microscopy, in situ spectroscopy and density functional theory calculations (DFT), we confirmed the formation of intermetallic compounds (IMCs) nanoparticles in Pt/MXenes catalysts after reducing a Pt precursor with MXene supports at elevated temperatures. Moreover, we proposed that Pt undergoes a three-stage transformation from single atoms to IMCs on the surface of MXenes, which shed light on the mechanism of the RMSI. Last, we designed MXene supported Pt catalysts for a wide range of catalytic processes such as water-gas shit reaction, light alkane dehydrogenation and electrochemical hydrogen evolution reaction.

Copyright Owner

Zhe Li

Language

en

File Format

application/pdf

File Size

128 pages

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