Grant: Discovery Grants Program - Individual

Our research in electrochemistry and electrocatalysis consists of three innovative thrusts that will be concurrently pursued to gain molecular-level understanding of electrochemical phenomena, discover new properties of materials, and develop new theories of electrochemical processes. We will synthesize Pd nanoparticles (Pd-NPs) of controlled shape and size, and characterize their structures and compositions using materials science methods (transmission electron microscopy, TEM, X-ray diffraction, XRD, electron tomography, ET). Their H absorbing capacity will be examined using electrochemical techniques (cyclic-voltammetry, CV, chrono-amperometry, CA, and chrono-coulometry, CC). The amount of absorbed H will be related to the size and shape of Pd-NPs to identify parameters that define their absorbing capacity. Absorption isotherms will be prepared to examine thermodynamics of the process and materials science techniques to analyze the structure of Pd-NPs upon H ingress. We will investigate composition-size-structure-reactivity phenomena in electrocatalysis by studying mechanisms and kinetics of the oxygen reduction and evolution reactions (ORR, OER). We will synthesize Pt, PtNi and PtCo nanoparticles and single crystals, and employ them as catalysts for ORR and OER. Their activity will be evaluated using electrochemical techniques (Tafel plots, polarization curves, CV, and CA). Electrochemical and analytical techniques (inductively coupled plasma mass spectrometry, ICPMS) will be used to examine degradation of these materials. Structure and composition of the electrode materials prior to and after electrochemical measurements will be analyzed using TEM, XRD, ET, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Comparison of results will shed light on composition-size-structure-reactivity phenomena and properties. Mass changes that accompany interfacial electrochemical processes are poorly understood and require examination over a broad temperature range. We will develop and apply variable-temperature electrochemical quartz crystal nanobalance (VT-EQCN) to examine interfacial electrochemical processes, such as catalyst oxidation and degradation. The technique will reveal T-dependent structure-forming and structure-breaking processes. The research program creates an opportunity for breakthroughs and discoveries. It is ambitious and challenging but my well-trained HQP are able to successfully undertake difficult projects. Though the research is fundamental in nature, it will benefit electrochemical technologies by creating new knowledge. Finally, HQP trained as part of this project will acquire knowledge in electrochemistry and electrocatalysis, and will develop a unique set of inter-disciplinary skills, which will enhance their future careers.