Professor Chuang investigates the structure of adsorbed species and its reactivity by transient infrared (IR) techniques. These techniques combined with traditional characterization methods such as XRD, UV-Vis, NMR, SEM, and TEM have been used for studying the nature of adsorbed species during oxygenate synthesis, hydroformylation, partial oxidation, reduction of nitric oxide, nitric oxide decomposition, oxidative carbonylation, photocatalytic oxidation and reduction, carbon dioxide adsorption, and reactions on solid oxide fuel cell catalysts. The objectives of his research program are (i) developing an understanding of the reactivity of adsorbed species and its associated sites, (ii) using mechanism information to guide catalyst and sorbent preparation, and (iii) scaling up of catalytic and adsorption processes from laboratory scale to the pilot scale.
Determination of the reactivity of adsorbates under reaction conditions has been a major challenge in the fundamental research of heterogeneous catalysis. Transient infrared technique is an experimental method which couples in situ infrared spectroscopy with isotopic transient approaches. This technique allows the reaction and adsorption on solid surfaces to be studied under their working conditions. The overall goal of this program is to develop a fundamental understanding of mechanisms of catalytic reaction and adsorption processes by investigating the relationships among the surface states and the composition of catalysts, the structure and coverage of adsorbates and their reactivity, and the macroscopic reaction kinetics.
Capture of CO2 from flue gas is technically feasible, but is not cost-effective using the currently available technologies. The objective of this project is to develop an efficient and low-cost CO2 capture solid sorbent which is highly resistant to SO2 poisoning and thermal degradation. The research efforts focus on fine-tuning the basicity, dispersion, and distribution of immobilized amines on a series of porous solids which have large pore, high surface area, and/or high thermal conductivity.
Carbon-based fuel cell is an effective approach for electric power generation because of its simplicity. The basic principle of the carbon-based fuel cell is that oxygen anion diffused from electrolytes directly electrochemically oxidizes carbon fuel to CO2 on the anode catalyst surface. This project involves fabrication of fuel cell and 5 kW fuel cell stack, investigation of electrochemical oxidation mechanisms on the anodes, development of fuel cell stack manufacturing process, and economic analysis.
In photocatalytic reactions, charge carrier generation and charge transfer steps occur in time scales of femtoseconds and nanoseconds, whereas the overall conversion of organics to CO2/ H2O occurs in a time scale of minutes to hours and the conversion of CO2/H2O to organics in a time scale of hours and days The goal of this project is to identify the rate-determining step by determining the structure of infrared-observable species, its reaction pathway and the correlation between the reactivity of adsorbed species and the relative concentration of photo-generated electrons.