The origin of the exceptionally high activity (B, Ag)-codoped TiO(2) catalysts under solar-light irradiation has been investigated by XPS and (11)B solid-state NMR spectroscopy in conjunction with density functional theory (DFT) calculations. experimental results demonstrated that a portion dopant Ag (Ag(3+)) ions were implanted into crystalline lattice close proximity to interstitial B (B(int.)) sites, forming [B(int.)-O-Ag] structural units. In situ experiments employed follow evolution...

A facile method has been developed for fabricating selective and sensitive electrochemical sensors the detection of toxic metal ions, which invokes incorporation palladium nanoparticles (Pd NPs) on porous activated carbons (PACs). The PACs, were derived from waste biomass feedstock (fruit peels), possess desirable textural properties porosities favorable dispersion Pd NPs (ca. 3–4 nm) graphitic PAC substrate. Pd/PAC composite materials so fabricated characterized by a variety different...

ConspectusSolid acid materials with tunable structural and acidic properties are promising heterogeneous catalysts for manipulating and/or emulating the activity selectivity of industrially important catalytic reactions. On other hand, performances acid-catalyzed reactions mostly dictated by features, namely, type (Brønsted vs Lewis acidity), amount, strength, local environment sites. The latter is relevant to their location (intra- extracrystalline), possible confinement Brønsted–Lewis...

A novel class of mesoporous aluminosilicate molecular sieves has been prepared by replication from carbon (CMKs) using zeolite precursors and characterized a variety analytical spectroscopic techniques, such as XRD, N2 adsorption/desorption, SEM/TEM, IR, hyperpolarized (HP) 129Xe, 31P MAS NMR. These replicated materials (RMMs), namely RMM-1 RMM-3 CMK-1 CMK-3, were found to exhibit structures respectively analogous Al-MCM-48 Al-SBA-15 but possess unique microporous characteristics due the...

The structures and local environments of boron species in B-doped (B, N)-codoped TiO2 photocatalysts have been investigated by solid-state 11B NMR spectroscopy conjunction with density functional theory (DFT) calculations. Up to seven different sites were identified the anatase TiO2, which may be classified into three categories, including interstitial, bulk BO3/2 polymer, surface species, has supported results obtained from FT-IR XPS as well DFT Two types interstitial borons, namely...

High surface area carbon porous materials (CPMs) synthesized by the direct template method via self-assembly of polymerized phloroglucinol-formaldehyde resol around a triblock copolymer were used as supports for nickel nanoparticles (Ni NPs). The Ni/CPM fabricated through microwave-assisted heating procedure have been characterized various analytical and spectroscopic techniques, such X-ray diffraction, field emission transmission electron microscopy, vibrating sample magnetometry, gas...

Post-synthetic dealumination treatment is a common tactic adopted to improve the catalytic performance of industrialized zeolitic catalysts through enhancements in acidity and stability. However, among possible extra-framework aluminum (EFAL) species dealuminated zeolites such as Al3+, Al(OH)2+, AlO+, AlOOH, Al(OH)3, presence tri-coordinated EFAL-Al3+ species, which exhibit large quadrupolar effect due lack hydrogen-bonding was normally undetectable by conventional one- two-dimensional 1H...

Highly porous beetroot-derived activated carbons incorporated with well-dispered magnetite nanoparticles (Fe3O4 NPs; average size ca. 3.8 ± 0.5 nm) were fabricated via a microwave-assisted synthesis route. The magnetic Fe3O4@BRAC catalysts so-fabricated characterized by variety of diffent physicochemical teniques, viz. XRD, FE-TEM, VSM, gas physisorption/chemisorption, TGA, XPS, Raman, ICP-AES, and FT-IR spectroscopy. as-prepared exploited for heterogeneous-phase reduction series...

A novel method for detecting an environmental pollutant, 4-nitrophenol (4-NP), by exploiting biomass-derived activated carbon (AC) is reported. The electrochemical performances of the 4-NP sensor were assessed cyclic and linear sweep voltammetries. presence oxygen surface functional groups heteroatoms (72.6% C, 6.1% H, 6.5% N, 7.5% S) in AC with high area (1555 m2 g−1) are found to be responsible excellent catalytic activities reversible redox behaviors observed during detection 4-NP....

Remarkable developments have been accomplished in silica-supported palladium nanoparticles (PdNPs)-mediated organic transformations for the generation of Suzuki (C–C), Heck (C═C), and Sonogashira (C≡C) coupling reactions academic as well industrial communities. Various synthetic methods were adopted to prepare highly dispersed PdNPs encapsulated within various forms silica supports. The type reaction examined size shape, stability, recycling ability PdNPs, influence different parameters on...

Schematic representation of direct synthesis a biomass-derived ZAC nanocomposite as practical platform for prospective applications.

Neutral ketene is a crucial intermediate during zeolite carbonylation reactions. In this work, the roles of and its derivates (viz., acylium ion surface acetyl) associated with direct C–C bond coupling reaction have been theoretically investigated under realistic conditions further validated by synchrotron radiation X-ray diffraction (SR-XRD) Fourier transformed infrared (FT-IR) studies. It has demonstrated that confinement effect significant influence on formation, stability, transformation...

A new methodology is reported for concurrent qualitative and quantitative characterization of internal external acid sites in zeolitic catalysts. H−ZSM-5 zeolites with varied Si/Al ratios have been examined by solid-state 31P MAS NMR using different adsorbed probe molecules, namely trimethylphosphine oxides (TMPO) tributylphosphine oxide (TBPO), conjunction elemental analysis. Up to seven distinct resonance peaks at 86, 75, 67, 63, 53, 43, 30 ppm were identified from the spectra TMPO. The...

Well-dispersed, highly stable PtRu nanoparticles of ca. 2–3 nm on carbon mesoporous materials (PtRu-CMMs) were synthesized directly using SBA-15 silica as the template, furfuryl alcohol and trimethylbenzene primary source, platinum ruthenium acetylacetonates cofeeding metal precursors. Results obtained from X-ray diffraction photoelectron spectroscopy show that Pt in PtRu-CMMs was present form a face-centered cubic (fcc) crystalline structure alloyed composed mainly Ru oxides, Ru(0), Pt(0)...

A comprehensive study has been made to probe the spatial proximities among different acid sites in dealuminated H-Y zeolites modified with various degrees of calcination, steam, and treatments by using a variety solid-state NMR techniques, including multinuclear MAS two-dimensional 1H double-quantum (DQ) spectroscopy. The effects dealumination on nature, concentration, location extraframework Al species were followed DQ hydroxyl protons conjunction 1H, 27Al, 29Si results. It was found that...

The validity of using 31P NMR adsorbed trimethylphosphine (TMP) as a probe molecule for discerning the types (Brønsted vs Lewis) and strengths acid sites in solid catalysts have been studied by density functional theory (DFT) calculations. Brønsted with varied acidic covering from weak, strong, to superacid, mimicked 8T zeolite cluster models having different Si−H bond lengths hence proton affinities, were examined together Lewis systems metallic centers, e.g., BClnF3−n (n = 0−3), AlClnF3−n...

A comprehensive study has been made to predict the adsorption structures and 31P NMR chemical shifts of various trialkylphosphine oxides (R3PO) probe molecules, viz., trimethylphosphine oxide (TMPO), triethylphosphine (TEPO), tributylphosphine (TBPO), trioctylphosphine (TOPO), by density functional theory (DFT) calculations based on 8T zeolite cluster models with varied Si−H bond lengths. linear correlation between proton affinity (PA) was observed for each homologous R3PO molecules...

Near-monodisperse polyaniline (PANI) colloids with controlled particle size (55–90 nm) were prepared by disperse polymerization of aniline in the presence a steric stabilizer: polyvinylpyrrolidone (PVP). The silica-coated PANI colloidal nanospheres further subjected to pyrolysis treatment at different temperatures (400–950 °C) fabricate nitrogen-doped carbon shells (NCSs). NCSs so obtained found have controllable morphologies and pore sizes (13.4–23.2 nm). A possible structural evolution...

Palladium nanoparticles (Pd NPs) immobilized on a garlic skin-derived activated carbons (GACs) is reported. The morphology, structure, surface compositions, and textural properties of the GACs Pd@GAC catalyst were investigated by variety physicochemical characterization techniques, which revealed dispersion Pd NPs with average particle size ca. 21 nm sheet-like graphitized areas pore volumes as high 1836 m2 g–1 0.89 cm3 g–1, respectively. As result, loading 1–2 wt% exhibited superior...

Superior performances of mesoporous carbon supported Pd nanoparticles during catalytic reduction 4-nitrophenol (4-NP), C–C coupling, and sensitive detection 4-NP.