Dr Wen-Feng Lin

Dr W. F. Lin
BSc (Xiamen University), 1985
MSc (Xiamen University), 1988
PhD (Xiamen University), 1991

Examinations Officer
Reader in Physical Chemistry

Tel:     + 44 (0) 28 9097 4175
Fax:    + 44 (0) 28 9097 6524
E-mail: w.lin@qub.ac.uk

Research Keywords

Electrocatalysis
Fuel cells
In-situ FTIR spectroscopy
Nanomaterials
Electrocatalytic generation of ozone from water
Electrochemical energy and environmental systems
Electrochemical surface science

Publications

 

Research

The primary themes of my research are related to energy, environmental and water. Our research activities on both fuel cells and ozone generation & applications include fundamental & applied catalysis studies and the novel cell and stack design & fabrication. These projects have crossed interdisciplinary boundaries between chemistry and chemical engineering and required me to collaborate with a wide range of engineers and scientists. Two parallel research approaches have been followed to advance our research: (1) development and application of novel techniques capable of providing molecular information on a range of catalytic reactions (from steady states to intrinsic kinetics), and (2) incorporation of this information into the design of improved materials (catalysts), components, reactors, devices and systems.

Electrocatalysis

Electrocatalysis plays an important role in sustainable energy production, energy storage, clean chemical synthesis and many other areas such as electrochemical engineering and bioelectrochemical processes. Electrocatalysis can be defined as the heterogeneous catalysis of electrochemical reactions, which occur at the electrode-electrolyte interface and where the electrode plays both the role of electron donor/acceptor and of catalyst. It is essential to understand the relationship between electrochemical reaction mechanisms and catalytic properties of electrodes by studying the structure and composition of the electrode surfaces and the adsorbed layers on the electrode surfaces.

Cyclic voltammogram of the Ru(0001) in 0.1 M HClO₄

(2 x 2) LEED Pattern

(1 x 1) LEED Pattern

(1 ×1) RHEED with additional 3D reflections that belong to RuO₂(100) clusters with a mean cluster size of 1.6 nm.

RuO₂(100) formed from the electro-oxidation of Ru(0001) in perchloric acid solution.

In-situ FTIR spectroscopy

The early studies on the electrochemistry in the 1960s and 1970s were essentially limited by the classical current/voltage/time techniques then available; although providing a wealth of kinetic data, they lacked the ability to provide essential molecular information. Major breakthroughs in the understanding of the mechanism at the electrode/electrolyte interface were triggered in particular by the development, at the beginning of the 1980s, of in situ electrochemical infrared (IR) techniques, and of the evolution of straightforward experimental protocols for the production of ordered and well-defined single crystal electrodes of the Pt-group metals. Since then, many in situ IR studies have been reported on single-crystal surfaces, generally using in situ Fourier transform infrared (FTIR) spectroscopy and elucidating the role of key adsorbates, such as CO or other carbonaceous fragments in electro-catalytically-relevant reactions. CO can be detected on electrodes down to a few percent of a monolayer with FTIR, and the positions and intensities of the vibrational bands of the various adsorbed CO species provide information about the adlayer structure and interfacial environment. The overwhelming majority of in situ FTIR spectroelectrochemical measurements to date have been carried out at room temperature, because effective control of the temperature of an in situ electrochemical spectroscopic system is not straightforward. However, a number of reports have appeared in the recent literature concerning in situ FTIR spectro-electrochemical measurements carried out as a function of temperature, and a significant effect of temperature on surface electrochemistry and electro-catalysis has been observed. In our group, several novel in-situ/on-line FTIR systems have been commissioned for the heterogeneous catalysis, electro-catalysis, photo-electrocatalysis and general electrochemistry studies which provide rich molecular data.

Cyclic Voltammograms showing the electro-oxidation of CO on RuPt(111) electrodes

In-situ FTIR spectra showing the electro-oxidation of CO on
RuPt(111) electrode

In-situ FTIR system for catalysis (photo-electro-catalysis),
electrochemistry and photochemistry studies

In-situ FTIR spectra showing the electrochemical redox processes of [N(PPh₃)₂]₂[Os₁₀C(CO)₂₄] in
0.1 M NBu₄BF₄−CH₂Cl₂ at a glass carbon (left, figure 1) or platinum (right, figure 2) electrode.

In-situ FTIR spectra showing the electro-oxidation of CO on Ru(0001) electrode at 50 °C

Fuel cells and electrochemical energy Systems:

Fuel cells produce electricity through an electrochemical reaction between hydrogen (or hydrogen-containing fuels such as methanol and ethanol) and oxygen, with an efficiency up to 70 % and very low pollutant emissions. An important type of fuel cell is the Proton Exchange Membrane Fuel Cell (PEMFC), which operates typically in the range 50°C-130°C and is suitable for transport and portable applications, and for power co-generation in buildings. Although hydrogen-fed PEMFCs are commercial, finding several applications, there is increasing interest in the application of the technology with liquid fuels such as methanol and ethanol, i.e., Direct Methanol/Ethanol Fuel Cells (DMFC/DEFC). Ethanol is a renewable fuel and has a high specific energy density; however, it remains a challenge to find an effective catalyst to break the C-C bonding for the complete oxidation of ethanol to realize the full potential. Our research in this area includes the development of high performance and low cost nanostructure supported catalyst materials, novel membrane and ionic liquid electrolyte, novel fuel cell configurations and real time cell performance evaluations.

Fuel cell works by electro-catalysis

On-line FTIR spectroscopic studies of fuel cell performance

Comparison of a fuel cell performance using various liquid fuels.

On-line FTIR spectra showing the products of methanol oxidation at anode of the Direct Methanol Fuel Cell (DMFC) under various conditions.

Electrocatalytic generation of ozone from water for water and waste treatment

Our research efforts include further development of high performance and low cost nanostructure catalysts for improved ozone generator and explore a wide range of applications of ozone for water/waste treatment and green synthesis.

Principles of electrocatalytic generation of ozone from water