One-step synthesis of carbon-supported electrocatalysts

Carbon Deposition Mitigation Strategies in Proton-Conducting Solid Oxide Fuel Cells: A Case Study with Biomass Fuels

Methanol and ethanol, when used as biomass fuels, demonstrate distinct benefits compared to hydrogen in proton-conducting solid oxide fuel cells (PCFCs) applications. Nevertheless, employing these biomass fuels in PCFCs encounters a significant obstacle due to carbon deposition, adversely affecting the cells' longevity. To mitigate this issue, a dendritic pore channel anode design was implemented to optimize the fuel distribution and utilization efficiency. Additionally, the approach incorporates a co-reforming strategy of fuel and steam, operating the cell under stable output current conditions to mitigate carbon deposition in the cell. Furthermore, the integration of Ru-GDC nanofiber catalysts enhanced the cell's resistance to carbon deposition and improved its stability. Techniques such as argon and oxygen purging, along with thermal regeneration, were investigated for carbon removal. These approaches have proven to be effective in diminishing carbon buildup and restoring cell functionality. Applying these strategies, PCFCs equipped with Ru-GDC fiber catalysts, operating at a stable 700 °C current, demonstrated prolonged stability for 117 h with methanol and 96 h with ethanol, markedly surpassing the performance of untreated cells. These advancements not only alleviate carbon deposition issues in PCFCs utilizing methanol and ethanol but also enhance the potential of biomass fuels in PCFC applications.

Advancements in Plasma-Enhanced Chemical Vapor Deposition for Producing Vertical Graphene Nanowalls

In recent years, vertical graphene nanowalls (VGNWs) have gained significant attention due to their exceptional properties, including their high specific surface area, excellent electrical conductivity, scalability, and compatibility with transition metal compounds. These attributes position VGNWs as a compelling choice for various applications, such as energy storage, catalysis, and sensing, driving interest in their integration into next-generation commercial graphene-based devices. Among the diverse graphene synthesis methods, plasma-enhanced chemical vapor deposition (PECVD) stands out for its ability to create large-scale graphene films and VGNWs on diverse substrates. However, despite progress in optimizing the growth conditions to achieve micrometer-sized graphene nanowalls, a comprehensive understanding of the underlying physicochemical mechanisms that govern nanostructure formation remains elusive. Specifically, a deeper exploration of nanometric-level phenomena like nucleation, carbon precursor adsorption, and adatom surface diffusion is crucial for gaining precise control over the growth process. Hydrogen's dual role as a co-catalyst and etchant in VGNW growth requires further investigation. This review aims to fill the knowledge gaps by investigating VGNW nucleation and growth using PECVD, with a focus on the impact of the temperature on the growth ratio and nucleation density across a broad temperature range. By providing insights into the PECVD process, this review aims to optimize the growth conditions for tailoring VGNW properties, facilitating applications in the fields of energy storage, catalysis, and sensing.