相关论文: Atomic-scale 3D structural dynamics and functional…
Alloy nanocatalysts have found broad applications ranging from fuel cells to catalytic converters and hydrogenation reactions. Despite extensive studies, identifying the active sites of nanocatalysts remains a major challenge due to the…
Proton exchange membrane fuel cells hold promise as energy conversion devices for hydrogen-based power generation and storage. However, the slow kinetics of the oxygen reduction at the cathode imposes the need for highly active catalysts,…
Electrochemical energy and substance conversion devices involve complex electrode processes, characterized by multiple charge transfer steps, competing pathways, and various intermediates. Such complexity makes it challenging to enhance…
A series of First Principles calculations is undertaken to characterize and explain the enhancement of the catalytic activity of oxygen on top of very disordered nanomaterials of Pt. As the adsorption of OH fragment on top of the surfaces…
Pd-based electro-catalysts are a key component to improve the methanol oxidation reaction (MOR) kinetics from alcohol fuel cells. However, the performance of such catalysts is degraded over time. To understand the microstructural/atomic…
The activity of metal catalysts depends sensitively on dynamic structural changes that occur during operating conditions. The mechanistic understanding underlying such transformations in small Pt nanoparticles (NPs) of $\sim1-5$ nm in…
We report here results of our density functional theory based computational studies of the electronic structure of the Pd-Co alloy electrocatalysts and energetics of the oxygen reduction reaction (ORR) on their surfaces. The calculations…
Structural changes induced by chemical reactions critically determine the catalytic performance and mechanism. However, precise tracking of the three-dimensional (3D) atomic structural evolution of individual bimetallic nanocatalysts…
We report a rapid solution-phase strategy to synthesize alloyed PtNi nanoparticles which demonstrate outstanding functionality for the oxygen reduction reaction (ORR). This one-pot co-reduction colloidal synthesis results in a monodisperse…
This paper is devoted to study the electrochemical behavior of Pt catalyst in a polymer electrolyte fuel cell at various operating conditions and at different electric potential difference (also known as voltage) cycling applied in…
A small percentage of dopant atoms can completely change the physical properties of the host material. For example, chemical doping controls the electronic transport behavior of semiconductors and gives rise to a wide range of emergent…
Tailored Pt nanoparticle catalysts are promising candidates to accelerate the oxygen reduction reaction (ORR) in fuel cells. However, the search for active nanoparticle catalysts is hindered by laborious effort of experimental synthesis and…
Wide proliferation of low temperature hydrogen fuel cell systems, a key part of the hydrogen economy, is hindered by degradation of the platinum cathode catalyst. Here, we provide a device level assessment of the molecular scale catalyst…
We present an electron tomography method that allows for the identification of hundreds of electrocatalyst nanoparticles with one-to-one correspondence before and after electrochemical aging. This method allows us to track, in…
The nitrogen reduction reaction (NRR), as an efficient and green pathway for ammonia synthesis, plays a crucial role in achieving on-demand ammonia production. This study proposes a novel design concept based on dual-iron atomic sites and…
Oxygen reduction catalysts frequently suffer from degradation under harsh operating conditions, and the limited understanding of the underlying mechanisms hampers the development of effective mitigation strategies. In this study, we…
A simple method for the preparation of PdCo@Pd core-shell nanoparticles supported on carbon has been developed using an adsorbate-induced surface segregation effect. The stability and electrocatalytic activity for the oxygen reduction of…
We report on the development of two new Pt-free electrocatalysts (ECs) for the oxygen reduction reaction (ORR) based on graphene nanoplatelets (GNPs). We designed the ECs with a core-shell morphology, where a GNP core support is covered by…
Understanding O2 bubble nucleation and growth during the oxygen evolution reaction (OER) is crucial to comprehend their influences on catalytically active sites in the process. To achieve this goal, mapping the spatial variation of…
In this study, the dynamic oxidation state changes of pure Pt and 50at% PtPd alloy catalysts were investigated during a temperature ramp from 80 to 450 C under a reactive gas mixture of 500 ppm NO and 3 % Oxygen in Nitrogen atmosphere.…