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For the first time, three-dimensional Zeolitic Imidazole Framework (3D) ZIF-7 (Zn(BeIM)2, BeIM = benzimidazole) supported on two-dimensional (2D) Zn(BeIM)OAc (Zinc–Benzimidazole–Acetate) was synthesized by reacting Zn(OAc)2 and benzimidazole in a one-pot reaction. By modulating the amount of diethylamine during the reaction, the ZIF-7/Zn(BeIM)OAc with a 1 to 1 molar ratio was obtained when the reactant molar ratio of Zn(OAc)2 and benzimidazole was 1 to 1.5. It was found that 3D-ZIF-7 was synthesized first and then transformed into 2D-Zn(BeIM)OAc by the reaction with remaining Zn(OAc)2. The synthesized ZIF-7 (Zn(BeIM)2) supported on Zn(BeIM)OAc (1/1) showed enhanced catalytic performance in the methoxycarbonylation of aniline with dimethyl carbonate. The yield of methyl N-phenyl carbamate reached 92.0% in 2 h at 190 °C, which was higher than yields obtained using the single component catalysts ZIF-7 (69.9%) and Zn(BeIM)OAc (35.4%). Furthermore, this catalyst was successfully reused four times, maintaining an MPC yield of 92.0%–95.8%.

The load–displacement curves of flow drill screw (FDS) and high-speed bolt joining process (hereafter referred to as RIVTAC) joints between dissimilar materials are predicted via development of an artificial neural network (ANN) model. The predicted load–displacement curves accurately describe the joint strength and failure mode of joints. From a lap shear test with 14 material combinations of aluminum alloys and steels for FDS joints, it was found that the load–displacement curves of FDS joints could be classified as a pull-out of fastener, plate failure, and fastener failure. From a lap shear test with 10 material combinations of aluminum alloys and steels for RIVTAC joints, it was found that the failure modes of RIVTAC can be classified as a plate failure and fastener failure. With the obtained experimental results, the ANNs were trained to predict the load–displacement curves that include the failure modes and lap shear strengths of FDS and RIVTAC joints with the material properties and plate thicknesses. The coefficients of determination between the measured and predicted loads were 0.84 and 0.96 for the FDS and RIVTAC joints, respectively. This indicates that the trained ANNs exhibit a strong correlation between the measured and predicted loads. The errors of the predicted lap shear strength were within 15.2 % and 11.1 % for the FDS and RIVTAC joints, respectively. This study provides a systematic analysis of the characteristics of FDS and RIVTAC joints between dissimilar materials and an efficient and accurate tool for predicting the load–displacement curves of FDS and RIVTAC joints between dissimilar materials.

The Diels-Alder reaction of biomass-derived dimethyl 2,5-furandicarboxylate (DMFDC) with ethylene followed by dehydrative aromatization is a sustainable route for the production of terephthalic acid, a monomer used for the synthesis of polyethylene terephthalate (PET). In this work, a series of heteropolyacid (HPA) catalysts with different supports, in this case SiO2, TiO2 and ZrO2, and hetero-addenda atoms, here phosphotungstic acid (HPW), silicotungstic acid (HSiW) and phosphomolybdic acid (HPMo), were used as catalysts, and their structure-activity correlation in the conversion of DMFDC to terephthalate was examined based on the density and strength of the acid sites. Characterization by XRD and Raman indicated that the Keggin structures of HPAs were well preserved on the SiO2 support compared to other supports, resulting in strong Bronsted acidity. The silica-supported HPW and HSiW catalysts exhibited significantly higher activity for terephthalate production than other supports and HPMo catalysts, but their activity were not correlated with the total acidity as measured by NH3-TPD. In contrast, the catalyst acid strength, as determined by the NH3 desorption temperature, decreased in the order HPW/SiO2 > HSiW/SiO2 >> HPW/ZrO2 > HPW/TiO2 > HPMo/SiO2 and was well correlated with the turnover rate for terephthalate production, suggesting that the higher activity of HPW/SiO2 is at least partly due to its stronger Bronsted acidity and that promoting the dehydration step of this reaction is a key to improving the selectivity to terephthalate. The effects of reaction conditions, in this case the acid loading amount, solvent used, temperature, and time, were also investigated with the most active silica-supported HPW catalysts to optimize the terephthalate yield. The 25%-HPW/SiO2 catalyst demonstrated a remarkable terephthalate yield of ∼60% with almost complete conversion under the optimum condition.

Carbon monoxide (CO) is an important platform compound that can be transformed into various fine chemicals. However, CO manufactured by the conventional methods contains many other gases such as hydrogen, methane, nitrogen and carbon dioxide, and additional separation processes are required to utilize CO as a raw material. The current state-of-the-art techniques for separating CO have problems of high energy consumptions. There are needs for an alternate separation process. In this work, we developed a Ni-based adsorbent supported by petroleum-based activated carbon (PAC, BET > 1300 m2/g). The affinity and capacity for CO were evaluated by CO isotherm and CO temperature-programmed desorption. The selectivity to CO was evaluated by the breakthrough test of multicomponent gases (10% H2, 10% CO, 1% CH4, and 1% CO2 with He balance). Ni/PAC was doped with sulfur to increase the CO adsorption activity, and the sulfur-doped Ni/PAC (Ni/PACS) showed outstanding CO adsorption capacity, which is 9 times higher than that of the sulfur-free Ni/carbon adsorbent (Ni/PAC). The Ni/PACS could recover the CO to over 99% purity from the multicomponent gases. The sulfur-doped Ni/carbon adsorbent showed high affinity, high capacity, and high selectivity for CO separation.

The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO2 capture. This paper presents a water-lean CO2 capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K2Sol, is a sterically hindered diamine; because of the hindered amine site, K2Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K2Sol are 4.3 and 2.8 GJ/t CO2, respectively, indicating that K2Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K2Sol experiments. We also describe the superior properties of K2Sol in terms of the CO2 loading, cyclic capacity, regeneration temperature, and degradation.

Proton exchange membrane fuel cells (PEMFCs) are promising mobile power supply systems, and operate without noise or polluting emissions. Because the oxygen reduction reaction (ORR) at the cathode suffers from high overpotential and sluggish kinetics, many catalysts have been developed in efforts to enhance activity and durability for the ORR. However, most of them have complicated synthetic procedures which cannot be scaled-up easily, and have only been tested in a half-cell. High activity in a half-cell does not necessarily guarantee better performance in a single-cell. In this work, we synthesized an Au-doped PtCo/C catalyst using a simple method of gas-phase reduction and subsequent galvanic replacement, and its activity and durability were tested in a single-cell. When current densities were compared at 0.6 V after a durability test of 30,000 cycles in 0.6–1.0 V, the values were 1.40, 0.81, and 0.63 A cm−2 for the Au-doped PtCo/C, acid-treated PtCo/C, and commercial Pt/C catalysts, respectively. Co leaching was much less in the Au-doped PtCo/C. Density functional theory (DFT) calculations confirmed that surface oxygen species bound more weakly at the catalyst surface and migration of a Co atom (Co segregation) to the surface was suppressed in the presence of Au. This facile method can provide a more realistic strategy to design better ORR catalysts for PEMFC application.

Although chloride-ligated Pt compounds like (bpym)PtCl 2 , K 2 PtCl 4 , and (DMSO) 2 PtCl 2 has been reported to be highly active catalysts for the methane oxidation to methyl bisulfate (MBS) in oleum media, their applications is hampered by the catalyst deactivation to PtCl 2 . In this study, we investigated Pt black catalyzed methane oxidation, which has no ligand. A MBS yield of 82.1% with a selectivity of 96.5% was obtained at a catalyst loading of 1.6 mM at 180 °C, which proved the highest catalytic activity of Pt-black for this reaction. The reaction was thought to proceed by the dissolved Pt species, and no deactivation was observed during four consecutive experiments. However, at a concentration of over 30 mM, MBS yield fell due to the decomposition of MBS to CO 2 on the surface of heterogeneous Pt(0). Vacuum distillation experiments showed the potential for isolating MBS from the oxidation product mixture as a major component.

Electrochemical CO2 reduction reaction (CO2RR) has received much attention as a promising technology to reduce CO2 using renewable electricity, but it typically suffers from low CO2 solubility in aqueous phase and a high cell resistance of a conventional liquid phase reactor. Here, we report the CO2RR using a membrane electrode assembly that consists of gas diffusion electrode (GDE) and anion exchange membrane (AEM). The GDE enabled facile mass transfer of gaseous CO2 directly to the catalyst and the AEM could suppress hydrogen evolution reaction (HER) by increasing local pH at the catalyst. Various metal powders of Pd, Ag, Zn, Cu, Sn, Ru, Pt, Ni were tested as cathode catalysts. Pd and Ag showed high current density of >200 mA cm−2 at -3.0 V and faradaic efficiency >95% for CO production with a low cell resistance of

A ternary oxide catalyst composed of CuO Co3O4 CeO2 (CCC) has great potential for automotive exhaust treatment due to its excellent CO oxidation activity and high resistance against hydrocarbon inhibition. However, current CCC catalyst exhibits significantly lower hydrocarbon oxidation activity comparing to CO oxidation, and deactivation occurs severely after hydrothermal aging. Here, we show that a Mn-doped CCC (CCCM) catalyst exhibits enhanced activity and durability for C3H6 oxidation, while maintaining the high activity for CO oxidation. The Mn-doping prevented sintering and phase separation of the Co3O4 phase even after hydrothermal aging at 750 °C for 25 h. The Mn was selectively doped into Co3O4 by substituting Co3+ octahedral sites in the Co3O4 spinel structure. The presence of Mn with a larger cation radius induced lattice expansion of the Co3O4 phase with more surface active oxygen. This strategy can provide a facile way to develop better non-PGM catalysts for emission control.

A novel bifunctional catalyst that enables an efficient one-pot conversion of furfural into γ-valerolactone (GVL) has been developed by anchoring heteropolyacid (HPA) on Zr-Beta zeolite. The catalysts were prepared by a post-synthesis procedure, which consists of the dealumination of Al-Beta, incorporation of Zr into the beta framework through solid-state ion-exchange and impregnation of the HPA. Zr-Beta is used as a Lewis acid catalyst to catalyze the transfer hydrogenation of furfural and levulinic acid/ester using 2-propanol as a hydrogen donor. To deal with the inability of Zr-Beta to catalyze the hydrolytic ring-opening of furans toward GVL, phosphotungstic acid (HPW) and silicotungstic acid (HSiW) were introduced to the Zr-Beta as BrOnsted acid sites. The characterization of the catalysts using XRD, UV–vis and XPS as well as TPD of ammonia and FT-IR spectroscopy of the adsorbed pyridine revealed that the HPA/Zr-Beta possesses both isolated Lewis and BrOnsted acid sites. When they were applied to the one-pot cascade conversion of furfural, the initial activity of the HPA/Zr-Beta toward GVL production were 2–3 times greater than that for Zr-Beta due to the enhanced hydrolytic ring-opening of the furans promoted by the added BrOnsted acidity. Especially, HPW loaded Zr-Beta demonstrated a remarkable GVL yield of ∼70% at 433 K after 24 h due to its high thermal stability and stronger BrOnsted acidity, and its activity far surpasses that of the conventional Sn-Al-Beta zeolite (∼40%). Overall, this study demonstrates that an incorporation of HPA into Lewis acid Sn- or Zr-Beta zeolites is an effective strategy to create isolated Lewis and BrOnsted acid sites within a single catalyst, thereby allowing the selective cascade catalysis for the cost-effective production of high-value chemicals.

SO2 absorption behaviours of N,N-dimethylaniline (DMA), N,N-diethylaniline (DEA), N,N-dibutylaniline (DBA), and N-methyldiphenylamine (MDPA) — were investigated in dry and wet conditions. DMA showed the highest SO2 absorption capacity of 1.5 molSO2 molAbsorbent−1 in dry condition, while DBA showed the highest capacity of 1.75 molSO2 molAbsorbent−1 in wet condition. Raman analyses revealed that anilines captured SO2 by forming charge transfer complexes in dry condition and the interaction between SO2 and aniline decreased as the steric hindrance of alkyl aniline increased. In contrast, bisulfite-based acid-base salt was formed in the presence of water, and the capacity increased with an increasing basicity of the alkyl aniline.

The long-term reliability of MEMS devices related to the dielectric charging phenomenon is one of the main hurdles in the commercialization of these devices. This paper presents a comprehensive review of the dielectric charging and its associated reliability issues in capacitive micromachined ultrasonic transducers (CMUTs). Due to the ease of versatile fabrication and large bandwidth in immersion, CMUTs are one of the promising technologies for ultrasonic applications that require miniaturized transducers, but due to electrostatic actuation, CMUTs suffer from inherent dielectric charging issues. In this review, the effects of dielectric charging and discharging on the CMUT performance, modeling of dielectric charging, and the methods to mitigate the reliability issue due to dielectric charging are extensively discussed. The mechanisms of dielectric charging are presented in detail to demonstrate the effects of dielectric charging on the drift. Structural, operational, and material modifications suggested in the literature to improve the long-term reliability of CMUTs are also reviewed. It is concluded that these methods have improved the reliability issues to great extent but there is still a room for improvements such as through exploration of different dielectric materials.

The current chemical industry is encountering an urgent need for CO2 reduction. Producing CO and H2 from CO2 and H2O by using renewable electricity might be a feasible solution to produce “carbon-neutral” chemicals and fuels. Developing easily scalable catalysts is key to this. In this issue of Chem Catalysis, Hahn and co-workers show that Zn–Cu catalysts enable efficient CO2 electro-reduction.

Operating proton exchange membrane fuel cell (PEMFC) under low humidity is important for applications of small electrical devices such as drone. Hydrophilic catalyst is prepared by depositing Pt nanoparticles on oxygen-functionalized carbon supports while commercial Pt/C is used as hydrophobic catalyst. Dual catalyst layer (dual-CL) electrodes are prepared with an inner hydrophilic layer and an outer hydrophobic layer for a membrane electrode assembly (MEA), and it is applied for PEMFC under low humidity. The dual-CL MEA shows enhanced cell performance and durability than MEAs with a single hydrophobic or hydrophilic catalyst layer. Hydrophilicity in anode is the most important to enhance performance. Keywords: PEMFC, Low humidity, Dual catalyst layer, Functionalized carbon, Drone

Cobalt-based catalysts having different base strengths were prepared by controlling the amount of yttrium oxide (Y2O3). These catalysts were used for the facile one-pot synthesis of polyetheramine (PEA) from polypropylene glycol (PPG) through reductive amination. It is noticed that high hydrogen partial pressures up to 40 bar inhibit the formation of cobalt nitride and lead to a high PEA yield although it has been known that dehydrogenation from alcohol to ketone is the rate-determining step. The Y2O3-inserted Co-Pd/Molecular sieve13X catalyst also showed high activity toward PEA even at low hydrogen partial pressure. Y2O3 played a crucial role in giving basicity to the catalyst, which not only prevents the formation of cobalt nitride but also promotes hydrogenation of imine to amine at a wide range of H2 pressure. Thus Y2O3 inserted Co-Pd/Molecular sieve 13X provides unique performance toward enhancing the PEA yield while suppressing the catalyst deactivation caused by the cobalt nitride formation.

With the anticipation for a more connected world through the Internet of Things, there is still a strong demand for miniaturized chemical sensors. Here, we report on a miniaturized resonant chemical sensor based on a Capacitive Micromachined Ultrasonic Transducer (CMUT) with a low operating voltage suitable for portable gas sensor applications. Previously reported CMUT chemical sensors required a DC operating voltage (16∼50 V) higher than the supply voltages of common circuits (e.g., 1.8–5 V). Thus, additional circuitry such as a charge pump circuit often was required as a part of the sensor interface circuits to supply the DC voltage to CMUT. This resulted in additional power consumption and a larger footprint. In this work, the vacuum gap of the CMUT which determines the operating voltage was reduced to 50 nm through the development of a double oxidation process with a high wafer-level yield. We achieved a significantly smaller pull-in voltage (

In-situ glycerol aqueous phase reforming and phenol hydrogenation (IGAPH) was conducted with Raney Ni® at 180–240 °C for phenol to glycerol ratios from 0 to 4.88. Thermodynamic analysis of the complex IGAPH reaction system revealed the need to balance endothermic glycerol aqueous phase reforming (APR) and exothermic phenol hydrogenation reactions. It was found that maximum glycerol carbon selectivity for APR and maximum hydrogen selectivity for phenol hydrogenation occurred at 220 °C. Addition of phenol to glycerol APR increased glycerol conversion and glycerol carbon selectivity for APR. These observations can be attributed to an equilibrium shift to the forward APR reaction due to hydrogen consumption and suppression of competing parallel reactions by phenol hydrogenation. An initial rate model of the system suggests that IGAPH proceeds via the Langmuir-Hinshelwood mechanism and is rate-limited by phenol hydrogenation. Perspectives for future process development in terms of reaction heat and catalyst stability are provided.

Proton exchange membrane fuel cells (PEMFC) are regarded as a promising renewable energy source for a future hydrogen energy society. However, highly active and durable catalysts are required for the PEMFCs because of their intrinsic high overpotential at the cathode and operation under the acidic condition for oxygen reduction reaction (ORR). Since the discovery of the exceptionally high surface activity of Pt3Ni(111), the octahedral PtNi nanoparticles have been synthesized and tested. Nonetheless, their milligram-scale synthesis method and poor durability make them unsuitable for the commercialization of PEMFCs. In this study, we focus on gram-scale synthesis of octahedral PtNi nanoparticles with Pt overlayers (PtNi@Pt) supported on the carbon, resulting in enhanced catalytic activity and durability. Such PtNi@Pt catalysts show high mass activity (1.24 A mgPt−1) at 0.9 V (vs RHE) for the ORR, compared to commercial Pt/C (0.22 A mgPt−1). Single-cell performance and electrochemical impedance spectroscopy (EIS) were also tested. The PtNi@Pt catalysts showed enhanced current density of 3.1 A cm−2 at 0.6 V in O2 flow while the commercial Pt/C had the value of 2.5 A cm−2. After 30,000 cycles of the accelerated degradation test (ADT), the PtNi@Pt still showed better performance than the commercial Pt/C in a single-cell system. The Pt layers deposition could enhance the catalytic performance and durability of octahedral PtNi nanoparticles.

The valorization of waste is of prime importance for sustainable chemistry and replacement of fossil fuel-derived counterparts. However, existing synthetic methods are critically hampered by complicated and uncontrollable chemistry arising from heterogeneous sources. Herein, we demonstrate a separation-free, straightforward, and controllable chemical approach for the valorization of lignocellulosic biomass by conversion to heteroatom-doped and undoped carbon dots (CDs) and nanoporous carbons (CNs) via a novel mechanism. The incorporation of heteroatoms such as phosphorus (P), sulfur (S), and nitrogen (N) into the CDs and steam-activated CNs (aCNs) leads to changes in the electronic and surface properties, and affords morphological control based on the doping agents, for application to CO2 capture and supercapacitors. Controlling the chemical composition and structure of the CDs results in shifts and variations in the splittings of the PL peaks and fluorescence wavelength owing to the distinct optoelectronic features. The P, N, and S-doped aCNs (P-aCN, S-aCN, and N-aCN) have robust honeycomb, entirely exfoliated reed-like, and hollow isolated reed-like structures, respectively, with unique hierarchical porosity. N-aCN exhibits the highest CO2 capacity and regeneration capability owing to the existence of basic N-containing groups and the associated structural integrity. In terms of the supercapacitive performance, P-aCN achieves the highest capacitance owing to the pseudocapacitance of the P˭O bonds, whereas S-aCN leads to the best rate and cyclic capabilities owing to the unique porous structure and S-containing group. These distinctive energy and chemical storage behaviors of the CNs highlight the importance of controlling hierarchical structure and heteroatoms for improved ultracapacitive performance.

We have previously shown that an activated carbon-supported ruthenium catalyst promoted with ReO x (RuRe/AC) is highly active for the hydrodeoxygenation (HDO) of lignin-derived phenols (e.g., guaiacol). In this work, we have investigated the effect of carbon supports on the structure and HDO activity of bimetallic RuRe particles using three different carbon supports, i.e., activated carbon (AC), carbon black (Vulcan carbon, VC), multi-walled carbon nanotube (MWCNT). The MWCNT- and VC-supported catalysts show remarkably enhanced activity and hydrocarbon selectivity for the HDO of a range of phenolic molecules (i.e., guaiacol, eugenol, benzyl phenyl ether) compared to RuRe/AC. STEM-EDS and XPS analyses reveal that bimetallic RuRe particles are more common than monometallic Ru or Re particles in the VC- and MWCNT-supported catalysts, and hexavalent rhenium species are more easily reduced to tetravalent rhenium during the HDO reactions in these catalysts, suggesting that Ru and Re in close proximity are required for the efficient hydrogenolysis of phenols. The formation of bimetallic particles on the AC surface is likely hindered by high microporosity and high surface oxygen functionalities, both of which restrict the mobility of Re and Ru for assembly.

Insecure attachment styles have been known to predict greater burden in caregivers of dementia patients. However, it has not been tested how filial obligation, which refers to one's sense of duty on helping elderly parents and is especially pronounced in Asian cultures, is involved in that relationship. We sought to identify whether the association between attachment style and caregiver burden differs according to the degree of filial obligation in caregivers of dementia patients. To assess filial obligation in Korean participants, a Korean filial obligation measure was developed. Ninety-eight Korean female caregivers of dementia patients reported their attachment style, filial obligation, burden, and patient behavioral symptoms. Patients' cognitive abilities, daily activity levels, and global dementia severities were obtained from hospital records. When adjusting for caregiver and patient characteristics, greater attachment anxiety predicted higher burden, corroborating literature findings. However, the association of attachment avoidance with burden was contingent on filial obligation: When obligation was high, greater avoidance associated with lower burden, which contrasts with previous negative implications of attachment insecurity. This implies a buffering role of attachment avoidance among those highly obligated. In addition, obligation positively predicted burden among those low in avoidance. This study is the first one to investigate and find conditional associations between attachment style, filial obligation, and caregiver burden. Given that filial obligation tends to be higher in caregivers of Eastern countries, this study provides quantitative evidence that the caregiving process may be different for them.

In the attempt to reduce the high-cost and improve the overall durability of Pt-based electrocatalysts for the oxygen reduction reaction (ORR), density-functional theory (DFT) calculations have been performed to study the energetics of the elementary steps that occur during ORR on TiN(100)- and TiC(100)-supported single Pt atoms. The O2 and OOH* dissociation processes on Pt/TiN(100) are determined to be non-activated (i.e. “barrier-less” dissociation) while an activation energy barrier of 0.19 and 0.51 eV is found for these dissociation processes on Pt/TiC(100), respectively. Moreover, the series pathway (which is characterized by the stable OOH* molecular intermediate) on Pt/TiC(100) is predicted to be more favorable than the direct pathway. Our electronic structure analysis supports a strong synergistic co-operative effect by these non-oxide supports (TiN and TiC) on the reduced state of the single-atom Pt catalyst, and directly influences the rudimentary ORR steps on these single-atom platinized supports.

This study investigates the use of combination of metal and solid-base catalysts for effective depolymerization of lignin into monophenol-rich bio-oil in supercritical ethanol through a synergy of base-catalyzed solvolysis and metal-catalyzed hydrogenolysis. The results showed that a combined catalyst of Ru/C and MgO/ZrO2 resulted in a significant decrease in the molecular weight of bio-oil, an increase in the yield of phenolic monomers, and the improved deoxygenation degree of bio-oil compared to the single catalyst condition. The synergic role of metal and base catalysts during lignin depolymerization was examined through comprehensive analysis of reaction products.

Titania nanoparticles (TNPs) and titania nanotubes (TNTs) are prepared using facile sol–gel and hydrothermal methods, respectively. The individual and combined effects of TNPs and TNTs-based photoanode materials are tested for dye-sensitized solar cells applications. The higher power conversion efficiency of 5.43% is obtained for the combined photoanode (TNTs coated on to TNPs layer) than that of the individual ones.

The oxidative coupling of methane (OCM) using hybrid catalysts containing BaTiO3 perovskite and Mn-Na2WO4 exhibited high activity and high selectivity at low temperature: 66.3 % C2+ (olefins and paraffins) selectivity and 25.9 % C2+ yield at 700 °C which is 100 °C lower than that used for Mn-Na2WO4 catalysts (800 °C). Upon the preparation of complex catalysts, the insertion of Mn into BaTiO3 (BaTi(Mn)O3) and the formation of NaxMn(Ti)O2 improved the oxygen-supplying ability of the catalysts. Additionally, strong interactions between the WO42− anions and BaTi(Mn)O3 or NaxMn(Ti)O2 stabilized the WO42− anions on the surface and improved the methane activation ability of the catalysts for the favorable production of hydrocarbons. The nanoscopic modification of catalysts was confirmed using H2–temperature-programmed reduction, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy results.

Methane upgrading into more valuable chemicals has been a promising challenge. It was previously reported that highly oxidized Pd/CeO2 could produce ethane from methane. Here, we enhanced the ethane productivity by controlling oxygen mobility of the catalyst support and adding water adsorbents. Pd/Ce1-xPdxO2-y catalyst, in which Pd atom was doped at the ceria support, showed enhanced oxygen activation and oxygen transfer, improving the ethane productivity from 0.04 molC2H6/mmolSurfacePd/h in Pd/CeO2 to 0.57 molC2H6/mmolSurfacePd/h in Pd/Ce1-xPdxO2-y. In order to remove the water produced from methane oxidation, zeolite 13X was physically mixed with Pd/Ce1-xPdxO2-y. The water adsorbent could increase the ethane production significantly, especially at low temperatures. The ethane yield of 0.30 % could be obtained at 290 °C using gaseous O2 as an oxidant. This work can provide useful ways to enhance the yield of value-added products in oxidative methane conversion.

Zn(OAc)2-catalyzed carbonylation and decarboxylation of glycerol and urea for the synthesis of glycidol were conducted at 150 °C, 2.7 kPa for 2 h and 170 °C, 2.0 kPa for 1.5 h, respectively. When the reaction conducted in a one-pot consecutive way, the yield of glycidol was 20%. However, when the formed zinc glycerolate (Zn(C3H6O3)) was filtered out after the carbonylation, the yield increased to 50% with respect to the amount of glycerol, whereas the yields of glycidol were very low when other zinc salts such as ZnCl2, ZnSO4 and Zn(NO3)2, were used as catalysts. The high catalytic activity of Zn(OAc)2 for this carbonylation and decarboxylation of glycerol and urea could be ascribed to the formation of Zn(NH3)x(OAc)2, which was determined from IR and TOF-SIMS studies.

As part of an effort to prepare a refrigerant with zero ozone depletion potential (ODP) and with a low global warming potential (GWP), the catalytic dehydrofluorination of 1,1,1,2,3-tetrafluoropropane (HFC-245eb) is performed to produce 2,3,3,3-tetrafluoropropene (HFO-1234yf). Cr2O3 prepared by the sol-gel method (Cr2O3(SG)) exhibits good catalytic activity attributable to the formation of surface chromium oxyfluoride, which exhibits better catalytic activity with high-valent chromium and a larger fluorine content. The formation of chromium oxyfluoride from chromium oxide is achieved by in-situ fluorination in the early stage of dehydrofluorination, avoiding the conventional fluorination method using toxic HF.

The Diels-Alder cycloaddition of biomass-derived furans and subsequent dehydration are promising routes for the sustainable production of commodity chemicals such as p-xylene (PX). In this paper, we have investigated the catalytic performances of a range of phosphotungstic acid (HPW) and silicotungstic acid (HSiW) catalysts supported on various oxides, i.e., SiO2, Al2O3, TiO2 and ZrO2 and their structure-activity correlation in the conversion of 2,5-dimethylfuran (DMF) and ethylene to PX. The characterization studies of the catalysts using XRD, BET, Raman and 31P MAS-NMR spectroscopy reveal that all of the supported heteropolyacid (HPA) catalysts (except HPW/ZrO2) retain their Keggin structure on the surface of oxide supports. Results from ammonia- and n-propylamine-TPD studies show that all of the supported HPA catalysts possess well-defined Bronsted acid sites with the total acidity decreasing in the following order: HPA/SiO2 > HPA/Al2O3 > HPA/ZrO2 > HPA/TiO2. The conversion of DMF and the initial rate of PX production generally increase with an increase in the total acidity, with HPA/SiO2 being the most active catalyst. The turnover frequency of PX production for HPA/SiO2 is also considerably greater than those for the HPAs supported on Al2O3, ZrO2, and TiO2, which suggests that the higher activity of HPA/SiO2 is at least partly due to the enhanced strength of Bronsted acid sites. Both the silica-supported HSiW and HPW catalysts demonstrate remarkably high PX selectivity (82–85%) at high DMF conversion (91–94%) at 250 °C after 6 h reaction. The effects of reaction conditions such as acid loading, reaction temperature, and reaction time have also been investigated with the most active silica-supported HSiW catalysts to optimize the PX yield.

Background aims Major challenges in de-differentiated liposarcoma (DDLPS) therapy are the high rate of sequential recurrence (>80%) and metastasis (20–30%) following surgical removal. However, well-defined therapeutic strategies for this rare malignancy are lacking and are critically needed. Methods We investigated a new approach to DDLPS therapy with mesenchymal stromal cells expressing herpes simplex virus–thymidine kinase (MSC-TK). In an effort to evaluate this efficacy, in vitro cytotoxicity of MSC-TK against DDLPS cells was analyzed using an apoptosis assay. For pre-clinical study, the MSC-TK–induced reduction in recurrence and metastasis was validated in a recurrent DDLPS model after the macroscopic complete resection and lung metastasis DDLPS model. Results MSC-TK induced apoptosis in DDLPS cells by bystander effects via gap junction intracellular communication (GJIC) of toxic ganciclovir (GCV). Recurrent DDLPS models following no residual tumor/microscopic tumor resection and lung metastasis DDLPS models were established, which suggested clinical relevance. MSC-TK markedly reduced locoregional recurrence rates and prolonged recurrence-free survival, thus increasing overall survival in the recurrent DDLPS model. MSC-TK followed by GCV treatment yielded a statistically significant reduction in early- and advanced-stage lung metastasis. Discussion This therapeutic strategy may serve as an alternative or additional strategy by applying MSC-TK to target residual tumors following surgical resection, thus reducing local relapse and metastasis in these patients.

Alumina–carbon composite catalysts (Al2O3-S) were synthesized by reacting Al(NO3)3·9H2O and the polyether-based surfactant. With an increasing surfactant amount, the resulting Al2O3-S had an increased carbon content, surface area and acidic/basic sites concentration. Transfer hydrogenation of furfural to furfuryl alcohol using the catalyst revealed that Al2O3-S(7), which had the highest carbon content, had the highest catalytic activity: furfuryl alcohol yield of 95.8% at 130 °C for 6 h. During reuse of the catalyst, gradual deactivation of the catalytic activity was found. The main reason of the deactivation was found to the decreased aluminum content by leaching during the reaction.

A solvent-free α-alkylation of acetone with butanol and ethanol was conducted using a mixture of Pd/C and CaO as heterogeneous catalysts. After reaction at 180 °C for 20 h, alkylated products, including C5-C11 ketones and alcohols, were obtained with a total yield of 78.1%. After this α-alkylation, consecutive hydrodeoxygenation at 270 °C for 20 h under H2 at 500 psig yielded 74.7% C5–C11 alkanes based on the amount of acetone. The product could be used as a bio-gasoline. After alkylation, the catalyst was isolated and characterized using XRD, TGA, XPS, and TEM to elucidate the deactivation of the catalyst. The main reason was found to be decreased basicity of Ca species by conversion of CaO to CaCO3 during the reaction. The Pd/C particles were slightly agglomerated after alkylation, but still retained their catalytic activity during successive reuses for the alkylation reaction. In subsequent runs, the activity of the used catalyst could be recovered by adding a sufficient amount of CaO, or by decarboxylation of CaCO3 to CaO at 500 °C, under H2.

The dry reforming of methane (DRM; CH 4 + CO 2 ↔ 2H 2 + 2CO) can be a good way to utilize greenhouse gases for the production of valuable syn-gas. Ni-based catalysts have been used for this reaction; however, the Ni size effect and support effect were highly coupled and therefore could not be observed separately. Here, a unique catalyst in which the Ni nanoparticle size and support can be varied independently was devised. Highly uniform Ni nanoparticles with sizes of 2.6, 5.2, 9.0, and 17.3 nm were tested for DRM at 800 °C without a significant change in the Ni size, and overlayers of various metal oxides, including SiO 2 , Al 2 O 3 , MgO, ZrO 2 , TiO 2 , were tested with the 5.2 nm of Ni nanoparticles. The dependence of the CH 4 or CO 2 turnover frequency on the Ni size and support was evaluated separately. The 2.6 nm Ni nanoparticles showed 4.1 times higher methane turnover frequency than those with a size of 17.3 nm. When various metal oxide overlayers were tested with the same 5.2 nm Ni, Al 2 O 3 exhibited 4.3 times higher methane turnover frequency than SiO 2 . The independent observation of the effects of the Ni nanoparticle size and support will provide valuable guidelines for designing effective methane dry reforming catalysts.

In recent years, electricity demand response (DR) has attracted attention as the most cost-effective way to balance the electricity grid. This study analyzes the preferences of South Korean energy consumers on residential DR and calculated the potential capacity of peak reduction in summer. The estimation demonstrates that consumers have heterogeneous preferences for automated residential DR programs and highly value reducing their monthly electricity bills. A scenario analysis shows that approximately 60.0% of metropolitan consumers in South Korea would participate in a residential DR program, and the corresponding reduction in the peak load is forecasted to be approximately 1.74 GW.

This work investigates the promoting effect of Ca on CO2 hydrogenation to methane in the highly exsolved Ni particles of La1-xCaxNiO3 perovskite catalysts. TEM images presented that metallic Ni particles are exsolved to the surface under a reducing atmosphere. This exsolution behavior is observed until the Ca ratio (x) becomes 0.4, suggesting that the highly dispersed Ni particles formed by the exsolution can actively adsorb and dissociate H2 molecules. In-situ DRIFT spectroscopy reveals that the surface Ca-sites effectively adsorb CO2 molecules to form reactive carbonates species. XPS analyses and CO methanation tests further show that adding Ca negatively charges the adsorption sites and enhances the reactivity of CO. This surface coordination is optimized by incorporating 0.4 of Ca, presenting facile hydrogenation of CO molecules to CH4. Thus, incorporating 0.4 of Ca into the A-site of LaNiO3 demonstrated the optimized promoting effect on CO2 methanation.