Low-Temperature Methane Oxidation for Efficient Emission Control in Natural Gas Vehicles: Pd and Beyond

Summary: The study shows that Pd/SiO2 can be an active and durable catalyst for CH4 oxidation with higher activity than Pd/Al2O3 through simple reductive regeneration. It suggests that the deactivation of Pd/SiO2 mainly comes from the blockage of the Pd/PdO surface by the SiO2 overlayer formed during hydrothermal aging.

Summary: A series of methane oxidation catalysts were prepared by doping SBA-15 with different amounts of zirconia and loading with Pd and Pt. The catalysts were characterized and evaluated for methane oxidation, with the catalyst containing 15 wt% zirconia showing the best performance. The improved performance was attributed to the higher amount of reducible PtOx species near ZrO2 and the sulfur scavenging effect of zirconia.

Summary: The study shows that using methane oxidation catalyst (MOC) can effectively reduce methane slip emissions in LNG ships. The use of a special sulfur trap can protect MOC against sulfur poisoning to some extent, and regeneration done once a day can recover the efficiency of MOC.

Summary: This study focused on measuring methane emissions from non-associated natural gas well pads in California, finding that a small number of active well pads were responsible for the majority of emissions. The study also detected methane emissions from idle well pads with smaller magnitudes, suggesting the importance of identifying and fixing leaks to reduce emissions. Mobile measurement techniques proved to be effective in detecting emissions from more well pads compared to optical gas imaging cameras, indicating their potential in supporting leak detection and repair programs.

Summary: The study introduces a Pd(PdO)/Co3O4@SiO2 bimetallic oxide core-shell catalyst with improved catalytic activity in methane combustion, attributed to the enhanced metal interaction between Pd and Co in the core-shell structure. The weakening of the Co-O bond in the catalyst promotes the release of lattice oxygen species to enhance the catalytic performance at low temperatures.

Summary: The study found that Pd loading impacts the size and chemical form of Pd particles, with Pd on the catalyst surface increasing in size due to sintering and PdO being reduced to metallic Pd and PdOx. The proportion of metallic Pd and/or reduced Pd oxide on the total surface area correlates linearly with the apparent reaction rate constants.

Summary: Developing energy-efficient alternatives for methane purification and capture is significant and challenging. A nickel-based metal-organic framework with abundant adsorption sites shows excellent separation performance.

Summary: The milling of Palladium acetate and CeO2 under dry conditions results in robust and environmentally friendly catalysts with excellent methane oxidation activity. The characterization techniques used in this study identified the presence of Pd-0/Pd2+ species with different degrees of interaction with ceria (Ce3+/Ce4+), which are believed to be responsible for the enhanced catalytic activity. This study provides insight into the mechanistic understanding of the catalytic performance of Pd/CeO2 catalysts prepared by dry milling.

Summary: This study tested the use of a UAV equipped with a remote sensing methane detector for detecting natural gas leaks in pipeline networks. Machine learning methods were used to analyze the collected data to identify spatially correlated regions with increased methane concentrations.

Summary: The study demonstrates that Pd/Ba-Al2O3 catalysts with Ba addition exhibit superior performance in wet methane oxidation, attributed to their favorable location and enhanced O-2 activation capability.

Summary: C2H2 and H-2, as important chemical and energy raw materials, can be produced effectively and environmentally friendly by the partial oxidation (POX) of CH4. We propose a fluorescence noise eliminating fiber-enhanced Raman spectroscopy (FNEFERS) technique to simultaneously analyze the intermediate gas compositions in the multiprocess of POX. This study demonstrates the ability of FNEFERS to replace gas chromatography for simultaneous and multiprocess analysis of intermediate compositions and monitor other chemical and energy production processes.

Summary: The study investigated the effects of sulfidation factors on the structure and performance of Mo-based catalysts, finding that the optimal sulfidation conditions were around 500 degrees C for 1 hour, with two simultaneous MoS2 formation routes identified during the process. A relationship between catalyst structure and catalytic performance was established, suggesting that edge Mo atoms cooperate with neighboring surface Mo sites to catalyze the reaction.

Summary: This study focused on the optimisation of Ce-promoted Co3O4 catalysts for the oxidation of traces amounts of methane. Lattice distortion caused by controlled amounts of Ce insertion increased the abundance of Co3+ and improved the redox properties and mobility of lattice oxygen species in the Co-Ce catalysts. The optimal catalyst formulation was found to be 10%Co3O4wt. with a Ce/Co molar ratio of 0.05, showing reasonable stability under cycled dry/humid conditions.

Summary: During coal mining, a significant amount of methane is released into the atmosphere annually, intensifying the greenhouse effect. Microbial methane oxidation technology offers a novel approach for reducing methane emissions and controlling methane in coal mines. Mixed methanotrophic consortia were selected from the natural environment to enhance the adaptability of microorganisms. These consortia exhibited robust growth during the 4th-10th days, peaking on the 7th day. The microbial metabolism increased the solution's pH and decreased the oxidation-reduction potential (ORP), showing a negative correlation between the two. The selected consortia displayed exceptional methane-oxidizing ability, leading to a 71.19% decrease in methane gas volume. Notably, the microorganisms maintained methane oxidation capacity even after the device's oxygen was depleted. The results demonstrated that the mixed methanotrophic consortia adjusted their population structure to adapt to environmental changes and continued exhibiting methane oxidation ability. The contact angle between the bacterial solution and coal sample surface was significantly lower than that of pure water and culture medium. Microorganisms adsorbed onto the coal sample's surface through self-movement, substantially improving the contact ability. Retention of microorganisms in the coal sample was influenced by flow velocity and particle size. Low flow velocity and a large contact area enhanced the contact efficiency of microorganisms on the coal surface. Mixed methanotrophic consortia offer high application value and feasibility for reducing methane emissions in coal mining and treating underground methane.