Summary

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Overview of our research

The overarching goal of our research is to develop new synthetic strategies for well-defined nanocrystals and 2-dimensional (2D) materials with atomically precise surfaces and interfaces that can lead to the fundamental understanding of how atomic structure affects catalyst performance and to use this new knowledge to design optimized catalysts for critical energy conversion and chemical transformation processes. We specifically focus on electrochemical CO2 conversion, sustainable nitrogen cycling, and heterogeneous thermocatalytic reactions (e.g., semihydrogenation of acetylene, hydrogenolysis of polyolefins).

Our research aims to address three questions fundamental to catalysis: (1) what are the catalytic active sites and how do they evolve under reaction conditions? (2) how to steer the reaction pathway toward desirable products via modulating active sites and their environments? (3) how to circumvent or ultimately, go beyond adsorption-energy scaling relations?

Three major tasks will be performed: (1) precision synthesis, characterization, and catalytic studies of well-defined nanostructured catalysts with controllable parameters; (2) bridging the gap between ex-characterization and dynamically-evolving structural motifs relevant to catalysis through in-situ/operando probes; (3) investigation of reaction mechanisms and revealing the structure-property relationships via a combination of spectroscopic, electron microscopic, and chemical analyses. 

Research directions and tasks

1. Precision synthesis

We’re developing new synthetic strategies for advanced materials, including monodisperse nanocrystals, high surface area 2-dimensional materials, and assemblies using colloidal chemistry and template-directed synthesis. Those well-defined functional materials will enable the development of new chemical/energy conversion processes and have far-reaching potential in many other fields.

Fig 2
Material Library of our nanoparticles with various morphology and 2-dimensional materials.

 

2. Electrocatalysis

The ever-increasing demand for clean energy and foreseeable change of natural resource landscape has motivated the search for highly efficient and sustainable energy storage and conversion devices. Electrochemical-based energy devices/chemical converting schemes, such as fuel cells, electrochemical CO2 conversion, electrochemical N2 fixation, are promising approaches due to their high theoretical conversion efficiency and low environmental impact, allowing their potential applications as alternatives to traditional chemical/energy conversions in automobile, stationary grids, portable electronics and chemical production. However, their costs and efficiencies have to be substantially improved before the large-scale practical applications, which is to a large extent dependent on the optimization of catalysts in these schemes. In our lab, we explore electrochemical applications of the advanced materials fabricated by us. The reactions of interest include the electrochemical conversion of CO2, N2, CH4, etc.

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Bi nanoparticles for efficient electrochemical CO2 reduction.

 

3. Heterogeneous catalysis

One fundamental question of traditional heterogeneous catalysis is how to bridge the gap between model and industrial catalysts? Our research is based on well-defined materials with controllable size, morphology, crystalline structure, facet, and tunable interfacial site between catalysts and supports. In quest of effective methods to steer the heterogeneous reaction activity and selectivity during catalysis, we specifically aim to fine-tune the electronic and geometric effects in well-defined materials to steer catalytic activity and selectivity.

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Pt nanoparticles on vacancy-abundant boron nitride nanosheets for CO oxidation.

 

Our project has three major tasks:

1) Synthesis, characterization and catalytic study of well-defined nanostructured catalysts with controllable parameters; 2) tailoring the interfacial architectures between catalysts and their concomitants to tune the physicochemical properties of catalytically-active center; 3) in-situ surface investigation on the reaction mechanism and revealing the structure-property relationship via a combination of spectroscopic, electron microscopic and chemical analysis.