Redefining the Role of Cobalt Oxide in Ethane Dehydroaromatization: Insights into Enhanced Catalytic Activity and Stability.

Cobalt is recognized as an active catalyst in ethane dehydroaromatization (EDA) reactions due to its efficient ethane cracking capability. In order to optimize cobalt's strong ethane cracking capability, it was loaded onto HZSM-5 zeolite through impregnation. This study was conducted with Co-loaded HZSM-5 catalysts with an incipient wetness impregnation method and witnessed an increase of catalytic activity with a long induction period.

Abatement of photochemical smog precursors through complete hydrocarbon oxidation over commercial Pd catalysts under fuel-lean conditions with NO promoting effect.

Currently, severe environmental issues have led to a great transition in the automotive industry from internal combustion engine vehicles to electric vehicles, but this transition will take time more than 10 years, which still requires the use of internal combustion engine vehicles. However, these vehicles emit a significant amount of hydrocarbons, in addition to nitrogen oxides (NO), due to incomplete fuel combustion. They contribute to the formation of photochemical smog when they react with NO in the presence of sunlight.

Transducer-Aware Hydroxy-Rich-Surface Indium Oxide Gas Sensor for Low-Power and High-Sensitivity NO Gas Sensing.

Low-power metal oxide (MOX)-based gas sensors are widely applied in edge devices. To reduce power consumption, nanostructured MOX-based sensors that detect gas at low temperatures have been reported. However, the fabrication process of these sensors is difficult for mass production, and these sensors are lack uniformity and reliability.

Excellent activity and selectivity of Pd/ZSM-5 catalyst in the selective catalytic reduction of NO by H.

Superior de-NO activity and N selectivity of the Pd/ZSM-5 catalyst was observed at low temperature (<200 °C) for the selective catalytic reduction of NO by H (H-SCR). Various Pd/ZSM-5 catalysts were prepared by calcinating at different temperatures (e.g.

spectroscopic studies of the effect of water on the redox cycle of Cu ions in Cu-SSZ-13 during selective catalytic reduction of NO.

The effect of water on the NH-assisted selective catalytic reduction of NO (NH-SCR) has been largely neglected, despite the inevitable presence of water vapor in real emissions produced by fuel combustion. In this work, we investigated the role of water in the behavior of active Cu ions in Cu-SSZ-13 in the NH-SCR reaction. The addition of water to the reactant feed leads to significantly increased NO reduction over the catalyst.

Upgrading bio-oil model compound over bifunctional Ru/HZSM-5 catalysts in biphasic system: Complete hydrodeoxygenation of vanillin.

A complete hydrodeoxygenation(HDO) of vanillin to yield cycloalkanes was performed using bifunctional Ru loaded HZSM-5 catalysts with different metal loadings (0.1, 0.5, 1, 3, and 5 wt%) and Si/Al ratios (Si/Al = 23,300) in n-octane/water biphasic system.

Mobility of Cu Ions in Cu-SSZ-13 Determines the Reactivity of Selective Catalytic Reduction of NO with NH.

Selective catalytic reduction of NO with NH (NH-SCR) in Cu-SSZ-13 has been proposed to have a unique homogeneous-like mechanism governed by the spatial proximity of mobile Cu ions. Among factors that determine the proximity, the effect of ion density on the SCR reaction is well established; however, it has not been verified how the different mobility of the Cu ion influences the SCR reaction. Herein, we try to reveal the mobility-dependent SCR reaction by controlling the Cu species with different ion mobilities in Cu-SSZ-13.

Enhanced activity of vanadia supported on microporous titania for the selective catalytic reduction of NO with NH: Effect of promoters.

Vanadium oxide-based catalysts are considered a promising catalyst for selective catalytic reduction (SCR) of NO with NH, which is an effective NO removal technology. As environmental issues have garnered more attention, however, improvements to vanadium-based SCR catalysts are strongly required. In a previous study, we found that vanadium oxide on microporous titania as a support (V/MPTiO) has certain advantages, such as improved thermal stability and more suppressed NO formation, over the use of conventional nanoparticle titania (DT-51) as a support.

Simple physical mixing of zeolite prevents sulfur deactivation of vanadia catalysts for NO removal.

NO abatement has been an indispensable part of environmental catalysis for decades. Selective catalytic reduction with ammonia using VO/TiO is an important technology for removing NO emitted from industrial facilities. However, it has been a huge challenge for the catalyst to operate at low temperatures, because ammonium bisulfate (ABS) forms and causes deactivation by blocking the pores of the catalyst.

Time-resolved observation of VO/TiO in NH-SCR reveals the equivalence of Brønsted and Lewis acid sites.

The involvement of Lewis and Brønsted acid sites on VO/TiO catalyst in the selective catalytic reduction of NO with NH (NH-SCR) is under debate. Here, a Li doping strategy is applied to selectively block Brønsted sites, which aims to prepare model catalysts with the same V loading but different ratios of the two acid sites. Time-resolved in situ DRIFTS observation demonstrates that the surface ammonia species pre-adsorbed on Lewis and Brønsted sites can participate equally in the reaction.

One-pot conversion of alginic acid into furfural using Amberlyst-15 as a solid acid catalyst in γ-butyrolactone/water co-solvent system.

One-pot conversion of alginic acid, which was derived from brown algae, to furfural was investigated using various solid acid catalysts. Among the solid acid catalysts tested, Amberlyst-15 showed the highest activity in furfural production in aqueous media. When the effect of reaction media was examined by applying various organic solvent mixtures, it was found that γ-butyrolactone/water co-solvent system was selected as the most appropriate system for the reaction.

Recent advances in catalytic co-pyrolysis of biomass and plastic waste for the production of petroleum-like hydrocarbons.

The global economy is threatened by the depletion of fossil resources and fluctuations in fossil fuel prices, and thus it is necessary to exploit sustainable energy sources. Carbon-neutral fuels including bio-oil obtained from biomass pyrolysis can act as alternatives to fossil fuels. Co-pyrolysis of lignocellulosic biomass and plastic is efficient to upgrade the quality of bio-oil because plastic facilitates deoxygenation.

Oxidative Methane Conversion to Ethane on Highly Oxidized Pd/CeO Catalysts Below 400 °C.

Methane upgrading into more valuable chemicals has received much attention. Herein, we report oxidative methane conversion to ethane using gaseous O at low temperatures (<400 °C) and atmospheric pressure in a continuous reactor. A highly oxidized Pd deposited on ceria could produce ethane with a productivity as high as 0.

Effect of Reactant Ratios on Methane Oxychlorination Over CeO₂ Catalyst.

The oxidative chlorination of methane to produce chloromethane (CH₃Cl, CM) over CeO₂ catalyst was investigated as a function of various reactant ratios to obtain the optimum condition with the highest yield of the target product (CH₃Cl). The reactions were carried out at 480 °C by changing O₂ and HCl concentrations at fixed CH₄ concentration. It was found that the ratio of O₂:HCl (1:2) is the most important parameter to obtain high CH₄ conversion and CH₃Cl selectivity.

Rotation-Assisted Hydrothermal Synthesis of Thermally Stable Multiwalled Titanate Nanotubes and Their Application to Selective Catalytic Reduction of NO with NH.

Titanate nanotubes are widely applied in various fields, including photocatalysts and electronic devices, but their weak thermal stability limits their application for catalyst support. Here, we found that titanate nanotubes with a thick multiwalled structure of 15 layers or more can be prepared by using rotation-assisted hydrothermal synthesis. The porous structure of conventional nanotubes synthesized without rotation collapsed easily after thermal treatment, whereas the nanotubes having a thick multiwalled structure retained their pore structure and the specific surface area (∼300 m/g) even after calcination at 400 °C in air.

Direct methanol synthesis from methane in a plasma-catalyst hybrid system at low temperature using metal oxide-coated glass beads.

A plasma-catalyst hybrid system was used to synthesize methanol directly from methane. A dielectric barrier discharge (DBD) plasma combined with the catalyst was introduced in order to overcome the difficulties of catalyst-only batch reactions such as high reaction pressure and separation of liquid product. Of the transition metal oxides, MnO-coated glass bead showed the highest methanol yield of about 12.

Investigation on the enhanced catalytic activity of a Ni-promoted Pd/C catalyst for formic acid dehydrogenation: effects of preparation methods and Ni/Pd ratios.

In this present work, we studied the effects of preparation methods and Ni/Pd ratios on the catalytic activity of a Ni-promoted Pd/C catalyst for the formic acid dehydrogenation (FAD) reaction. Two catalysts prepared by co-impregnation and sequential impregnation methods showed completely different Pd states and catalytic activities. As the sequentially impregnated catalyst showed better activity than the co-impregnated catalyst, the sequentially impregnated catalyst was investigated further to optimize the ratio of Ni/Pd.

Catalytic Hydrogenation of Macroalgae-Derived Alginic Acid into Sugar Alcohols.

Alginic acid, a major constituent of macroalgae, iss hydrogenated into sugar alcohols over carbon-supported noble metals for the first time. Mannitol and sorbitol are the major products of the catalytic hydrogenation of alginic acid, which consists of two epimeric uronic acids. The main reaction pathway is the consecutive hydrogenations of the aldehyde and carboxyl ends of alginic acid dimers, followed by the cleavage of the C-O-C linkage into monomeric units by hydrolysis.

Sulfation and Desulfation Behavior of Pt-BaO/MgO-Al2O3 NOx Storage Reduction Catalyst.

The comparative study between Pt-BaO/Al2O3 and Pt-BaO/MgO-Al2O3 gives the information about the effect of MgO addition to Al2O3 support on the sulfation and desulfation behavior of Pt-BaO/MgO-Al2O3 NOx storage reduction catalyst. The sulfated two samples were analyzed by using element analysis (EA), X-ray diffraction (XRD), H2 temperature programmed reaction (H2 TPRX) and NOx uptake measurement. The amount of sulfur uptake on 2 wt% Pt-20 wt% BaO/Al2O3 and 2 wt% Pt-20 wt% BaO/MgO-Al2O3 are almost identical as 0.

Roles of Promoters in V2O5/TiO2 Catalysts for Selective Catalytic Reduction of NOx with NH3: Effect of Order of Impregnation.

Recently, various promoters for commercial selective catalytic reduction (SCR) catalysts are used to improve DeNOx activity at low temperature. We aimed at finding the optimum condition to prepare V2O5/TiO2 catalyst by changing promoters (W, Ce, Zr and Mn), not only for improving SCR reactivity, but also for reducing N2O formation at high temperature. In addition, we changed the order of impregnation between promoter and vanadium precursors on TiO2 support and observed its effect on activity and N2O selectivity.

Suppressed N2O formation during NH3 selective catalytic reduction using vanadium on zeolitic microporous TiO2.

Emission of N2O from mobile and off-road engine is now being currently regulated because of its high impact compared to that of CO2, thereby implying that N2O formation from the exhaust gas after-treatment system should be suppressed. Selective catalytic reduction using vanadium supported TiO2 catalyst in mobile and off-road engine has been considered to be major source for N2O emission in the system. Here we have demonstrated that vanadium catalyst supported on zeolitic microporous TiO2 obtained from the hydrothermal reaction of bulk TiO2 at 400 K in the presence of LiOH suppresses significantly the N2O emission compared to conventional VOx/TiO2 catalyst, while maintaining the excellent NOx reduction, which was ascribed to the location of VOx domain in the micropore of TiO2, resulting in the strong metal support interaction.

Removal of NO(x) at low temperature over mesoporous alpha-Mn2O3 catalyst.

Low-temperature selective catalytic reduction was carried out over various kinds of manganese oxide (MnOx) catalysts. Mesoporous alpha-Mn2O3, commercial bulk Mn2O3, and Mn/SBA-15 were used as the catalyst. The NOx removal performances of the catalysts were compared.

Catalytic characteristics of titanium oxide/MCM-41 synthesized by liquid phase atomic layer deposition.

Titanium oxide on MCM-41 was synthesized using the atomic layer deposition (ALD) method. BET, XRD, NH3-TPD and EDS were used to study the structural properties of the supported titanium oxides. The surface area of catalysts decreased with increasing of the amount of titanium in precursor solution.

Butanol Dehydration over V₂O₅-TiO₂/MCM-41 Catalysts Prepared via Liquid Phase Atomic Layer Deposition.

MCM-41 was used as a support and, by using atomic layer deposition (ALD) in the liquid phase, a catalyst was prepared by consecutively loading titanium oxide and vanadium oxide to the support. This research analyzes the effect of the loading amount of vanadium oxide on the acidic characteristics and catalytic performance in the dehydration of butanol. The physical and chemical characteristics of the TiO₂-V₂O₅/MCM-41 catalysts were analyzed using XRF, BET, NH₃-TPD, XRD, Py-IR, and XPS.

Preparation of highly dispersed tungsten oxide on MCM-41 via atomic layer deposition and its application to butanol dehydration.

Highly dispersed tungsten oxide on MCM-41 was synthesized using a novel atomic layer deposition (ALD) method. BET, XRD, XPS, NH3-TPD, and pyridine-IR were used to study the physicochemical properties of the supported tungsten oxides. In this study, the maximum loading of tungsten oxide on MCM-41 that could be prepared using the modified ALD method was 27.