Abstract Taming interfacial electronic effects on Pt nanoparticles modulated by their concomitants has emerged as an intriguing approach to optimize catalytic performance. Here, we report assembled vacancy-abundant hexagonal boron nitride nanosheets and use a model catalyst embrace effect induced the with N-vacancies B-vacancies for superior CO oxidation catalysis. Experimental results indicate that strong interaction exists between vacancies. Bader charge analysis shows B-vacancies, serve...

Three primary amine materials functionalized onto mesoporous silica with low, medium, and high surface coverages are prepared evaluated for binary CO2/H2O adsorption under dilute conditions. Enhancement of efficiency due to humid is most pronounced low coverage materials. In situ FT-IR spectra adsorbed CO2 on these suggest this enhancement may be associated the formation bicarbonate species during coverage, though such not observed On lowest loading, longer time scales adsorption, but only...

The role of Lewis and Brønsted sites in the dehydration glycerol on niobium oxide Na+-exchanged is investigated using FTIR spectroscopy supported by DFT calculations. Glycerol impregnated catalysts at room temperature an ex-situ method. Under high vacuum conditions, forms a stable multidentate alkoxy species through its primary hydroxyl groups with sites. When coordinated this way, C–O bonds are polarized, favoring position to form hydroxyacetone. In contrast, secondary alcohol group...

Ceria has recently shown intriguing hydrogenation reactivity in catalyzing alkyne selectively to alkenes. However, the mechanism of reaction, especially activation H2, remains experimentally elusive. In this work, we report first direct spectroscopy evidence for presence both surface and bulk Ce-H species upon H2 dissociation over ceria via situ inelastic neutron scattering spectroscopy. Combined with ambient-pressure X-ray photoelectron spectroscopy, IR, Raman spectroscopic studies, results...

The nature of the surface species formed through adsorption CO2 on amine-grafted mesoporous silica is investigated in situ FTIR spectroscopy with aid 15 N dynamic nuclear polarization (DNP) and 13 C NMR spectroscopy. Primary, secondary, tertiary amines are functionalized onto a SBA-15 silica. Both isotopically labeled natural-abundance used for accurate peak assignments, which compared assignments reported previously. results support formation monomeric dimeric carbamic acid secondary that...

The measurement of isosteric heats adsorption silica supported amine materials in the low pressure range (0–0.1 bar) is critical for understanding interactions between CO2 and sites at coverage hence to development efficient adsorbents capture from flue gas ambient air. Heats an array silica-supported are experimentally measured using a Calvet calorimeter equipped with customized dosing manifold. In series 3-aminopropyl-functionalized materials, higher densities resulted adsorption, clearly...

Single-walled carbon nanotube (SWCNTs) is a promising material candidate for fabricating high-performance electrodes in electrochemical capacitors. An intriguing question what are the key characteristics of SWCNTs that influence performance SWCNT-based capacitors? We grafted with different amounts carboxylic groups by surfactant free method. Their density was quantified using fluorescence labeling method, ranging from 7.3 to 353.2 nmol m−2. were also characterized scanning electron...

The formation and evolution of surface species during the hydrodeoxygenation various bio-oil model compounds (anisole, m-cresol, guaiacol) over Pt/HBEA HBEA is investigated. Anisole m-cresol form phenate cresolate on Lewis acid sites, while guaiacol can chemisorb more strongly forming bidentate species. position functional groups within these molecules has a strong influence degree Pt/HBEA, due to steric hindrance C–O scission step. Consequently, highest yield deoxygenated products formed...

The stability of a 1 wt % Pt/γ-Al2O3 catalyst was tested in an ethanol/water mixture at 225 °C and autogenic pressure, conditions which it is possible to dissolve depolymerize various kinds lignin, structural changes the catalysts were studied by means X-ray diffraction (XRD), 27Al MAS NMR, N2 physisorption, transmission electron microscopy (TEM), H2 chemisorption, elemental analysis, thermogravimetric analysis-mass spectrometry (TGA-MS), IR. In absence reactants alumina support found...

Although perovskite catalysts are well-known for their excellent redox property, acid–base reactivity remains largely unknown. To explore the potential of perovskites in catalysis, we made a comprehensive investigation this work on properties and series selected perovskites, SrTiO3, BaTiO3, SrZrO3, BaZrO3, via combination various approaches including adsorption microcalorimetry, situ FTIR spectroscopy, steady state kinetic measurements, density functional theory (DFT) modeling. The surfaces...

Abstract The chemical oxidation of activated carbon by H 2 O and SO 4 is investigated, structural modifications are characterized, the materials used as catalysts for hydrolysis cellulose. Treatment with enlarges pore size imparts functional groups such phenols, lactones, carboxylic acids. treatment targets edges sheets primarily, this effect more pronounced a higher temperature. Adsorption isotherms demonstrate that adsorption oligomers on functionalized dominated van der Waals forces....

The water gas shift (WGS) reaction is of paramount importance for the chemical industry, as it constitutes, coupled with methane reforming, main industrial route to produce hydrogen. Copper–chromium–iron oxide-based catalysts have been widely used high-temperature WGS industrially. mechanism by CuCrFeOx catalyst has debated years, mainly between a "redox" involving participation atomic oxygen from and an "associative" proceeding via surface formate-like intermediate. In present work,...

The exchanged Ga(<sc>iii</sc>) sites are the active for promoting BTX formation during ethanol conversion.

The atomistic structure and morphology (shape size) of nanomaterials have strong influences on their physical chemical properties. However, many characterization techniques focus exclusively one length-scale regime or another when developing quantitative morphology/structural models. In this article, we demonstrate that powder X-ray diffraction neutron pair distribution function (PDF) can be used to obtain accurate average {001} {101} faceted anatase TiO2 nanocrystals based differential...

To gain an in-depth understanding of the surface properties relevant for catalysis using ternary oxides, we report acid–base pair reactivity shape-controlled SrTiO3 (STO) nanocrystals dehydrogenation ethanol. Cubes, truncated cubes, dodecahedra, and etched cubes STO with varying ratios (001) (110) crystal facets were synthesized a hydrothermal method. Low-energy ion scattering (LEIS) analysis revealed that on is enriched SrO due to reconstruction, resulting in high ratio strong base sites....

Methane conversion has received renewed interest due to the rapid growth in production of shale gas. combustion for power generation and transportation is one alternatives methane utilization. However, complete critical minimize negative environmental effects from unburned methane, whose noxious effect 25 times greater than that CO2. Although perovskite catalysts have high thermal stability, their low activities prevent them being utilized on a commercial basis. In this work, we show impact...

Although perovskites have been widely used in catalysis, tuning of their surface termination to control reaction selectivity has not well established. In this study, we employed multiple surface-sensitive techniques characterize the (one aspect reconstruction) SrTiO3 (STO) after thermal pretreatment (Sr enrichment) and chemical etching (Ti enrichment). We show, by using conversion 2-propanol as a probe reaction, that STO can be controlled greatly tune catalytic acid/base properties...

An ultrastable Au nanocatalyst based on a heterostructured perovskite support with high surface area and uniform LaFeO3 nanocoatings was successfully synthesized tested for CO oxidation. Strikingly, small nanoparticles (4–6 nm) are obtained after calcination in air at 700 °C under reaction conditions. The designed catalyst not only possessed extreme sintering resistance but also showed catalytic activity stability because of the strong interfacial interaction between support.

Activated carbon is functionalized by different treatments with sulfuric acid and hot liquid water used as catalyst for the hydrolysis of cellobiose in a continuously operated fixed bed reactor. Characterization results reveal that chemically treated materials are more disordered lower degree graphitization, while adsorption isotherms demonstrate van der Waals forces dominate interaction between carbohydrates surface catalysts. All catalysts stable during under flow conditions. Carbon...

Flexible framework dynamics present in the subset of metal–organic frameworks known as soft porous crystals give rise to interesting structural properties that are unique this class materials. In work, we use experiments and molecular simulation understand highly dynamic nanorotor behavior 1,4-diazabicyclo[2.2.2]octane (DABCO) ligand pillared Zn-DMOF Zn-DMOF-TM (TM = tetramethyl) structures. While DABCO is be displaced presence water parent structure, variation stable even after adsorbing...

Abstract Solid oxide‐supported amine sorbents for CO 2 capture are amongst the most rapidly developing classes of sorbent materials capture. Herein, basic γ supports used as hosts sites through grafting 3‐aminopropyltrimethoxysilane to alumina surface under a variety conditions, yielding expected surface‐grafted alkylamine groups, demonstrated by FTIR spectroscopy and 29 Si 13 C cross‐polarization magic‐angle spinning (CPMAS NMR) spectroscopy. Grafting on in presence water leads high density...

The kinetics and mechanism of methanol dehydration, redox, oxidative coupling were investigated at 300 °C under dilute oxygen concentration over anatase TiO2 nanoplates truncated-bipyramidal nanocrystals in order to understand the surface structure effect TiO2. two nanoshapes displayed both (001) (101) facets, with a higher fraction facet exposed on nanoplates, while dominated by facet. A kinetic study using situ titration ammonia shows that active sites for dehydration are acidic...