Palladium Nanoparticles on Modified Cellulose as a Novel Catalyst for Low Temperature Gas Reactions

Palladium was incorporated into carboxymethylated cellulose fibers as a support, thereby becoming an efficient and stable catalyst for low temperature gas phase reaction. Thus, NO was used as test molecule of Greenhouse Gas to be catalytically reduced with hydrogen on an eco-friendly sustainable material containing palladium as the active site. Prior to the catalytic test, the catalysts were reduced with glucose as an eco-friendly reagent. The material characterization was performed by SEM-EDS, XRD, LRS, TGA and FTIR.The catalytic results showed that at 170°C, NO conversion was 100% with a selectivity of 70% to nitrogen. While NOX species were completely converted into N2 at temperatures higher than 180°C. The starting commercial material Solucell® was also studied, but its performance resulted lower than the ones of functionalized fibers.The use of this strategy, i.e., the functionalization of cellulose fibers followed by in-situ formation of metallic nanoparticles, can be further applied for the design of a wide range of materials with interesting applications for gas and liquid phase reactions under mild conditions.

The Potential of Sustainable Biomass Producer Gas as a Waste-to-Energy Alternative in Malaysia

It has been widely accepted worldwide, that the greenhouse effect is by far the most challenging threat in the new century. Renewable energy has been adopted to prevent excessive greenhouse effects, and to enhance sustainable development. Malaysia has a large amount of biomass residue, which provides the country with the much needed support the foreseeable future. This investigation aims to analyze potentials biomass gases from major biomass residues in Malaysia. The potential biomass gasses can be obtained using biomass conversion technologies, including biological and thermo-chemical technologies. The thermo-chemical conversion technology includes four major biomass conversion technologies such as gasification, combustion, pyrolysis, and liquefaction. Biomass wastes can be attained through solid biomass technologies to obtain syngas which includes carbon monoxide, carbon dioxide, oxygen, hydrogen, and nitrogen. The formation of tar occurs during the main of biomass conversion reaction such as gasification and pyrolysis. The formation of tar hinders equipment or infrastructure from catalytic aspects, which will be applied to prevent the formation of tar. The emission, combustion, and produced gas reactions were investigated. It will help to contribute the potential challenges and strategies, due to sustainable biomass, to harness resources management systems in Malaysia to reduce the problem of biomass residues and waste.

Real-time imaging of accelerated solid-liquid-gas reactions with nanobubbles

Solid-liquid-gas reactions are ubiquitous. An understanding of how gases influence the reactions at the nanoscale is significant for achieving the enhanced triple-phase reactions. Here, we report a real-time observation of the accelerated etching of gold nanorods with oxygen nanobubbles in aqueous hydrobromic acid using liquid cell transmission electron microscopy (TEM). Our observation reveals that when an oxygen nanobubble is close to a nanorod below the critical distance (~1nm), the local etching rate is significantly enhanced with over an order of magnitude faster. Molecular dynamics simulations results show that the strong attractive van der Waals interaction between the gold nanorod and oxygen molecules facilitates the transport of oxygen through the thin liquid layer to the gold surface and thus plays a crucial role in increasing the etching rate. This result sheds light on the rational design of solid-liquid-gas reactions for enhanced activities.

Design and Validation of an Online Partial and Total Pressure Measurement System for Li-Ion Cells

Online Electrochemical Mass Spectrometry (OEMS) is capable of monitoring both partial and total gas pressure of Li-ion cells. Herein, the development and validation of an OEMS system along with detailed calibration protocols and limits of detection sensitivity are showcased. A full cell based on LiCoO₂/Graphite cell during overcharge to 4.9 V <i>vs.</i> Li/Li⁺ at 50 °C is investigated and the results are compared to LiCoO₂/LiFePO₄ and Graphite/LiFePO₄ cells in order to differentiate between gases forming at the anode and cathode. The release of O₂ from Li_xCoO₂ (x < 0.4) during both charge and discharge demonstrates that its degradation is dependent on composition rather than potential. Combining partial and total pressure measurements provides a clear advantage when detailing major and minor gas reactions as well as when determining unaccounted gases. The methodology presented herein provides a technical basis for deeper understanding of degradation reactions in batteries and electrochemical systems alike.

Design and Validation of an Online Partial and Total Pressure Measurement System for Li-Ion Cells

Online Electrochemical Mass Spectrometry (OEMS) is capable of monitoring both partial and total gas pressure of Li-ion cells. Herein, the development and validation of an OEMS system along with detailed calibration protocols and limits of detection sensitivity are showcased. A full cell based on LiCoO₂/Graphite cell during overcharge to 4.9 V <i>vs.</i> Li/Li⁺ at 50 °C is investigated and the results are compared to LiCoO₂/LiFePO₄ and Graphite/LiFePO₄ cells in order to differentiate between gases forming at the anode and cathode. The release of O₂ from Li_xCoO₂ (x < 0.4) during both charge and discharge demonstrates that its degradation is dependent on composition rather than potential. Combining partial and total pressure measurements provides a clear advantage when detailing major and minor gas reactions as well as when determining unaccounted gases. The methodology presented herein provides a technical basis for deeper understanding of degradation reactions in batteries and electrochemical systems alike.