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In the present work, the influence of alkali ions (Li, Na, K) on the structural and spectroscopic properties of silica glasses doped with Sm3+ was investigated. Infrared and Raman spectroscopy techniques were used to investigate the structural properties of the alkali silicate glasses. The optical absorption showed bands characteristic of Sm3+ ions in alkali silicate glasses, and this was investigated. The Judd–Ofelt theory was applied to evaluate the phenomenological intensity parameters (Ω2, Ω4, and Ω6) of the optical absorption measurements. The multi-channel visible and near infrared emission transitions originating from the 4G5/2-emitting state of the Sm3+ in alkali silicate glasses with a maximum phonon energy of ~1050 cm−1 were investigated. From the evaluated Judd–Ofelt parameters, radiative parameters such as spontaneous emission probabilities, radiative lifetimes, branching ratios, and stimulated emission cross-sections were calculated. The recorded luminescence spectra regions revealed intense green, orange, red, and near-infrared emission bands, providing new traces for developing tunable laser and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Alkali series with different atomic numbers affect the physicochemical properties of aqueous solutions. The micellar properties of aqueous solutions of dodecanoate as surfactants were measured by changing the counterions (C12-Na, C12-K, C12-Rb, and C12-Cs). A plot of Krafft temperature vs. alkali metal atomic number showed a downward convex curve, with its minimum temperature (20?) in the C12-K system. By contrast, a plot of the critical micelle concentration (CMC) vs. alkali metal atomic number exhibited an upward convex curve with the maximum CMC (25.6 mmol L-1) at C12-K. Furthermore, the minimum surface tension (?min) of the solution at the CMC increased with increasing atomic number (C12- Na ? C12-K < C12-Rb < C12-Cs). The size of the dodecanoate micelles decreased with increasing atomic number. The ionization degree of the micelles also increased with increasing atomic number of the alkali metal. Small-angle X-ray scattering (SAXS) measurements revealed that alkali dodecanoate micelles formed spherical to ellipsoidal structures. In addition, micelles from the shell region showed large electrostatic repulsion, judging from the shape of the spectrum in the higher Q-1 region. From the measurement results of the solubilization of naphthalene into the micelles, the size of the micelles corresponded to the maximum solubilization quantity of naphthalene. [ABSTRACT FROM AUTHOR]

Ni/CaO, a low-cost dual-functional material (DFM), has been widely studied for integrated CO2 capture and hydrogenation. The core of this dual-functional material should possess both good CO2 capture–conversion performance and structural stability. Here, we synthesized Ni/CaO DFMs modified with alkali metals (Na, K, and Li) through a combination of precipitation and combustion methods. It was found that Na-modified Ni/CaO (Na-Ni/CaO) DFM offered stable CO2 capture–conversion activity over 20 cycles, with a high CO2 capture capacity of 10.8 mmol/g and a high CO2 conversion rate of 60.5% at the same temperature of 650 °C. The enhanced CO2 capture capacity was attributed to the improved surface basicity of Na-Ni/CaO. In addition, the incorporation of Na into DFMs had a favorable effect on the formation of double salts, which shorten the CO2 capture and release process and promoted DFM stability by hindering their aggregation and the sintering of DFMs. [ABSTRACT FROM AUTHOR]

Complexes of the alkali metals Li-Cs with 3-thiophenecarboxylate (3tpc), 2-methyl-3-furoate (2m3fur), 3-furoate (3fur), 4-hydroxycinnamate (4hocin), and 4-hydroxybenzoate (4hob) ions were prepared via neutralisation reactions, and the structures of [Li2(3tpc)2]n (1Li); [K2(3tpc)2]n (1K); [Rb(3tpc)(H2O)]n (1Rb); [Cs{H(3tpc)2}]n (1Cs); [Li2(2m3fur)2(H2O)3] (2Li); [K2(2m3fur)2(H2O)]n (2K); [Li(3fur)]n(3Li); [K(4hocin](H2O)3]n (4K); [Rb{H(4hocin)2}]n.nH2O (4Rb); [Cs(4hocin)(H2O)]n (4Cs); [Li(4hob)]n (5Li); [K(4hob)(H2O)3]n (5K); [Rb(4hob)(H2O)]n (5Rb); and [Cs(4hob)(H2O)]n (5Cs) were determined via X-ray crystallography. Bulk products were also characterised via XPD, IR, and TGA measurements. No sodium derivatives could be obtained as crystallographically suitable single crystals. All were obtained as coordination polymers with a wide variety of carboxylate-binding modes, except for dinuclear 2Li. Under conditions that normally gave coordinated carboxylate ions, the ligation of hydrogen dicarboxylate ions was observed in 1Cs and 4Rb, with short H-bonds and short O...O distances associated with the acidic hydrogen. The alkali-metal carboxylates showed corrosion inhibitor properties inferior to those of the corresponding rare-earth carboxylates. [ABSTRACT FROM AUTHOR]

Catalytic reduction of a representative set of imines, both aldimines and ketimines, to amines has been studied using transfer hydrogenation from 1,4‐dicyclohexadiene. Unusually, this has been achieved using s‐block pre‐catalysts, namely 1‐metallo‐2‐tert‐butyl‐1,2‐dihydropyridines, 2‐tBuC5H5NM, M(tBuDHP), where M=Li–Cs. Reactions have been monitored in C6D6 and tetrahydrofuran‐d8 (THF‐d8). A definite trend is observed in catalyst efficiency with the heavier alkali metal tBuDHPs outperforming the lighter congeners. In general, Cs(tBuDHP) is the optimal pre‐catalyst with, in the best cases, reactions producing quantitative yields of amines in minutes at room temperature using 5 mol % catalyst. Supporting the experimental study, Density Functional Theory (DFT) calculations have also been carried out which reveal that Cs has a pathway with a significantly lower rate determining step than the Li congener. In the postulated initiation pathways DHP can act as either a base or as a surrogate hydride. [ABSTRACT FROM AUTHOR]

The monovalent cations sodium and potassium are crucial for the proper functioning of excitable cells, but, in addition, other monovalent alkali metal ions such as cesium and lithium can also affect neuronal physiology. For instance, there have been recent reports of adverse effects resulting from self-administered high concentrations of cesium in disease conditions, prompting the Food and Drug Administration (FDA) to issue an alert concerning cesium chloride. As we recently found that the monovalent cation NH4 C activates glycine receptors (GlyRs), we investigated the effects of alkali metal ions on the function of the GlyR, which belongs to one of the most widely distributed neurotransmitter receptors in the peripheral and central nervous systems. Whole-cell voltage clamp electrophysiology was performed with HEK293T cells transiently expressing different splice and RNA-edited variants of GlyR a2 and a3 homopentameric channels. By examining the influence of various milli- and sub-millimolar concentrations of lithium, sodium, potassium, and cesium on these GlyRs in comparison to its natural ligand glycine (0.1 mM), we could show that cesium activates GlyRs in a concentration- and post-transcriptional-dependent way. Additionally, we conducted atomistic molecular dynamic simulations on GlyR a3 embedded in a membrane bilayer with potassium and cesium, respectively. The simulations revealed slightly different GlyR-ion binding profiles for potassium and cesium, identifying interactions near the glycine binding pocket (potassium and cesium) and close to the RNA-edited site (cesium) in the extracellular GlyR domain. Together, these findings show that cesium acts as an agonist of GlyRs. [ABSTRACT FROM AUTHOR]

The selectivity of adsorption between alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) based on the ionic functional groups of the surfactants was studied using two types of surfactants, dodecanoic acid (DA) and sodium dodecyl sulfate (SDS), in the foam separation system. The results showed that Li+ was preferably removed by foam separation using DA. The removal rates of other alkali metal ions were relatively low, and there were no significant differences among other alkali metal ions (Na+, K+, Rb+, and Cs+). However, Cs+ exhibited the highest removal rate among the mixed alkali metals by foam separation using SDS. From these results, the selectivity of the alkali metal in foam separation was dependent on the type of surfactant. [ABSTRACT FROM AUTHOR]

The conversion of ethanol to synthesize various oxygenated hydrocarbons was studied over monometallic-, bimetallic-, and trimetallic-(K)(Co)MoS2-based catalysts supported on activated carbon. The catalysts were synthesized using the incipient wetness impregnation method and sulfidized with H2S. The catalysts were characterized by the following techniques: N2 adsorption-desorption, UV spectroscopy of pyridine-adsorption; scanning electron microscopy (SEM); SEM energy dispersive X-ray (EDX). SEM/EDX results revealed that the active metals formed a uniform phase. Synthesized catalysts were tested in a fixed-bed tubular reactor. It was established that the addition of K and Co significantly altered the physical-chemical properties, activity and selectivity of sulfide catalysts. The addition of K decreased the catalytic activity (i.e., over KMoS2/C and KCoMoS2/C) relative to the reference MoS2/C and CoMoS2/C samples. The incorporation of a promoter atom, Co, and an alkali metal, K, inhibited ethanol dehydration (into ethene) and intermolecular dehydration (into diethyl ether). K incorporation led to the formation of active sites for higher alcohol synthesis (HAS) and other oxygenates, namely (aldol-) condensation and coupling processes, and increased the ratio of liquids to hydrocarbons. Ethanol was transformed into ethyl acetate, ethyl acetoacetate, acetaldehyde, butonal-1, propanol-1, and short-chain hydrocarbons. The acidity of the catalysts did not have a direct influence on conversion. The obtained results led us to conclude that product yields are highly dependent on the active phase composition, with ethyl acetate being the most preferred product.

The monovalent cations sodium and potassium are crucial for the proper functioning of excitable cells, but, in addition, other monovalent alkali metal ions such as cesium and lithium can also affect neuronal physiology. For instance, there have been recent reports of adverse effects resulting from self-administered high concentrations of cesium in disease conditions, prompting the Food and Drug Administration (FDA) to issue an alert concerning cesium chloride. As we recently found that the monovalent cation NH4+ activates glycine receptors (GlyRs), we investigated the effects of alkali metal ions on the function of the GlyR, which belongs to one of the most widely distributed neurotransmitter receptors in the peripheral and central nervous systems. Whole-cell voltage clamp electrophysiology was performed with HEK293T cells transiently expressing different splice and RNA-edited variants of GlyR α2 and α3 homopentameric channels. By examining the influence of various milli- and sub-millimolar concentrations of lithium, sodium, potassium, and cesium on these GlyRs in comparison to its natural ligand glycine (0.1 mM), we could show that cesium activates GlyRs in a concentration- and post-transcriptional-dependent way. Additionally, we conducted atomistic molecular dynamic simulations on GlyR α3 embedded in a membrane bilayer with potassium and cesium, respectively. The simulations revealed slightly different GlyR-ion binding profiles for potassium and cesium, identifying interactions near the glycine binding pocket (potassium and cesium) and close to the RNA-edited site (cesium) in the extracellular GlyR domain. Together, these findings show that cesium acts as an agonist of GlyRs.

Chemical looping gasification (CLG) is an effective coal utilization technology. In this work, the CLG of bituminite was investigated through fixed-bed batch experiments using NiFe2O4 oxygen carrier (OC) to achieve high-quality syngas. The changes in the phase of the oxygen carrier during the chemical looping reaction and the reaction mechanism were explored. The results show that elevated temperature and adding a fraction of steam facilitate the gasification reaction. Adding an appropriate amount of ZrO2 into the NiFe2O4 and modification with alkali metal can enhance the performance of the oxygen carrier. A carbon conversion of 95% and a syngas (CO and H2) selectivity of 86% were obtained under the optimized reaction conditions of 950 °C, an oxygen-carrier-to-bituminite (O/B) ratio of 7:3, a NiFe2O4/ZrO2 ratio of 7:3, and a steam rate of 0.08 mL/min. Modification of the NiFe2O4 by doping alkali metal can significantly facilitate the CLG process. Alkali lignin ash has a more pronounced modifying effect on oxygen carriers than K2CO3. The NiFe2O4 OC underwent a gradual reduction in Ni2+ → Ni and Fe3+ → Fe8/3+ → Fe2+ → Fe processes during the gasification reaction phase. In addition, 20 redox cycles were conducted to demonstrate the oxygen carriers' good cyclic reaction performance in the CLG process. After 20 redox cycles, the carbon conversion rate was maintained at about 90%, and the syngas selectivity was stably kept at over 80%. This work laid the theoretical foundation for the clean and efficient use of bituminite. [ABSTRACT FROM AUTHOR]

Alkali metals, as ideal electron donors, can effectively regulate the valence state distribution of the host metals. Nevertheless, no studies have reported the application of alkali metal promoters in the hydrogen evolution reaction (HER). Here, we designed an efficient and wide pH-universal hydrogen evolution catalyst that utilizes alkali metal to control the valence, size, and dispersion of Ru NPs. The experimental results reveal that the alkali metal additives contribute to the dispersion and stabilization of metallic Ru. More importantly, the interaction between Na and Ru regulates the distribution of Ru valence states and helps to form more active components of Ru0. Additionally, NaCl functioned as an in situ template to assist the construction of a porous carbon skeleton promotes mass transfer and exposes more active sites, further promoting the synergistic effect of Ru and Na. As a result, the optimal Ru0.3/C−800 delivers high efficiency for HER with an overpotential as low as 29 mV in 1.0 M KOH and 83 mV in 0.5 M H2SO4 under 10 mA cm−2. Particularly, the catalytic performance of Ru0.3/C−800 even outbalanced that of commercial Pt/C in an alkaline medium. This rational construction strategy opens up new avenues for obtaining superior pH-universal electrocatalysts. [ABSTRACT FROM AUTHOR]

Alkali metals have been widely used as promoters of metal catalysts in various applications, yet the atomic understanding of the promotional mechanism remains elusive. In this work, we for the first time report the significant promotional effect of potassium to the Co-N-C single-atom catalyst for the direct dehydrogenation of ethylbenzene. K cation was introduced by impregnation of Co-N-C with KCl followed by calcination at 600 °C, which resulted in the bonding of K to the Co-O moiety of the Co-N-C catalyst as revealed by X-ray absorption spectroscopy in combination with theoretical calculations. The formation of Co-O-K moiety led to the increase of electron density at the O atom due to electron transfer of K to O, and consequently facilitated the heterolytic cleavage of the C-H bond of ethylbenzene across the Co-O moiety. The promotional effect of K was found to be a volcano-function with the K/Co ratio and became the greatest at the K/Co ratio of 1.36, which resulted in the highest steady-state reaction rate of 9.7 mmolEB·gcat−1·h−1 reported thus far. Moreover, the catalyst exhibited excellent stability during 100 h time on stream. [ABSTRACT FROM AUTHOR]

This article investigated the structure, and the spectroscopic and antimicrobial properties of mandelic acid and its alkali metal salts. The electron charge distribution and aromaticity in the analyzed molecules were investigated using molecular spectroscopy methods (FT-IR, FT-Raman, 1H NMR, and 13C NMR) and theoretical calculations (structure, NBO, HOMO, LUMO, energy descriptors, and theoretical IR and NMR spectra). The B3LYP/6-311++G(d,p) method was used in the calculations. The antimicrobial activities of mandelic acid and its salt were tested against six bacteria: Gram-positive Listeria monocytogenes ATCC 13932, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, and Loigolactobacillus backii KKP 3566; Gram-negative Escherichia coli ATCC 25922 and Salmonella Typhimurium ATCC 14028, as well as two yeast species, Rhodotorulla mucilaginosa KKP 3560 and Candida albicans ATCC 10231. [ABSTRACT FROM AUTHOR]

Activation of dinitrogen (N2) is the critical step in nitrogen reduction reaction (NRR) in ammonia synthesis. In this paper, reaction mechanisms of N2 activation on trimetallic clusters Mo2M (M = Li, Na, K, Mg, and Ca) and Mo3−xCax (x = 2–3) were systematically studied by density functional theory calculations. Unlike Mo2 which is inert to N2, clusters with alkali or alkaline earth metal atoms have much higher reactivity toward N2 in terms of both thermodynamics and kinetics. Particularly, in one reaction path of N2 with MoCa2, all the intermediates and transition states are well below the energy sum of the reactants, indicating that the dissociation of N2 on MoCa2 can take place spontaneously in gas-phase reactions. N2 transfers on clusters with different coordination modes, and the N−N bond is gradually activated. When N2 is bonded with three metal atoms with end-on: side-on: side-on coordination mode, it is fully activated and easily dissociated into two adsorbed N atoms. These results may serve as a prototype to design single-cluster catalysts with a trimetallic center for nitrogen activation and conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Na+ and Ca2+ can reduce the NH 3 -SCR activity and change the N 2 selectivity. • Zr modification improves the negative effect of Na+ on La-Mn perovskite oxides. • Zr doping did not improve the negative effect of Ca2+ on NH 3 -SCR activity. • The recovery of adsorption performance and redox ability is the key to the regeneration of the catalyst. The presence of alkali metal/alkaline earth metal in fuel gas is one of the important reasons for the deactivation of catalyst for selective catalytic reduction of NO x with NH 3 (NH 3 -SCR). In this work, the Na+/Ca2+ poisoning mechanisms of Zr-modified and unmodified La-Mn perovskite oxides for NH 3 -SCR reaction were studied. It is found that the deposition of Na+ into LaMnO 3 (LM) catalyst has a much larger effect than that of Ca2+, while such a result is opposite for the Na+/Ca2+-deposited La 0.8 Zr 0.2 MnO 3 (ZLM) catalysts. The deposition of Na+/Ca2+ compounds can block the pores and affect the adsorption and activation of NH 3 on the catalysts. After Zr modification, the catalyst with a higher Mn4+ content shows a better redox property and increased acid sites. These acidic sites can trap Na+, thereby delaying the catalyst poisoning and causing a better activity of ZLM catalyst than LM catalyst. The deposition of Ca2+ in the form of CaCO 3 on the catalyst surface leads to a serious pore blockage, showing a poor resistance to Ca2+. After regeneration, the pores of the catalyst are dredged, and the active sites originally occupied by Na+/Ca2+ are released, resulting in an recovery of catalyst activity. The recovery of adsorbed oxygen and Mn4+ content is the key factor for returning the SCR activity. [ABSTRACT FROM AUTHOR]

The control and modification of non-metallic inclusions are crucial in enhancing the deformability and production efficiency of cord steel. This study investigated the effects of Na2+ and K2+ on the morphology, composition and deformability of inclusions in cord steel by adding Na2CO3 and K2CO3. Scanning electron microscope equipped with energy-dispersive spectrometer and FactSage were applied to analyse the melting point and morphology of inclusions in ingots and forged samples. The results showed that the deformability of inclusions was improved and the melting point of inclusions decreased by adding Na2CO3 and K2CO3. These inclusions were in the form of long strips after forging. Moreover, the deformability of inclusions in steel increased more obviously by adding Na2CO3 than that with K2CO3. This study also found that the deformability of inclusions in sample with higher aluminium content was worse than that in sample with lower aluminium content. The inclusions can be deformed effectively under the condition of adding alkali metals into steel containing low aluminium content. [ABSTRACT FROM AUTHOR]

• [VO 2 L]− with Schiff base and alkali metals and ammonium as cations were studied. • The complexes have very good solubility in water. • The X-ray structure analysis with cation-anion distance determination was described. • The complexes are stable at pH=7 and in DMEM-high glucose cell culture media. • The complexes have better stability at pH=2 in contrast to their neutral analogues. Alkali metals (Li, Na, K, Rb and Cs) and ammonium salts were used in synthesis of [VO 2 L]− complexes (where L = ONO-donating Schiff base ligands derived from 2-hydroxybenzhydrazide and 5‑bromo- or 5-chlorosalicylaldehyde). All 12 compounds were characterized by elemental analysis, IR and UV–Vis spectra. For six complexes, the X-ray single crystal structures were determined and confirmed the general formula of the compounds as M[VO 2 L] (M = alkali metal or ammonium). The geometry as well as cation to vanadium distance were determined and discussed. The complexes have very good solubility in water and their stability in this solvent as well as at pH = 2 and in DMEM-high glucose cell culture media was tested by UV–Vis spectroscopy. [Display omitted] [ABSTRACT FROM AUTHOR]

Alkali-metal amides have become key reagents in synthetic chemistry, with special focus in deprotonation reactions. Despite the higher reactivity found in the heavier sodium and potassium amides, their insolubility and low stability has favoured the use of the more soluble lithium analogues, converting them into the most used non-nucleophilic bases. Studying the coordination effects of Lewis donor molecules such as tridentate amine PMDETA (N,N,N’,N’’,N’’-pentamethyldiethylenetriamine) in combination with the sodium amide NaTMP (TMP = 2,2’,6,6’-tetramethylpiperidide), we have been able to unlock the use of these reagents for the functionalisation of arenes, i.e. the deuterium incorporation by hydrogen isotope exchange and the deprotonative borylation of unactivated arenes. These findings show how sodium amides are not just a simple more sustainable replacement of their lithium counterparts, but also that they can display significantly enhanced reactivities allowing for the development of new transformations.

An attempt to synthesize a holmium sulfidotungstate using potassium polysulfides as reactive flux resulted in orange single crystals of K2[WS4], isotypic to K2[MoS4] (orthorhombic; Pnma; a=935.10(3), b=694.22(2), c=1221.85(4) pm; Z=4). A similar attempt to obtain a neodymium sulfidotungstate with sodium polysulfide yielded a violet substance, which underwent hydrolysis yielding orange‐yellow single crystals of Na2[WS4] ⋅ 4 H2O (monoclinic, C2/c, a=1098.08(4), b=904.46(3), c=1144.27(4) pm, β=101.577(3)°, Z=4). Further attempts to synthesize these products deliberately as single phase materials only proved to be successful for K2[WS4] but not for Na2[WS4] ⋅ 4 H2O. Both compounds contain non‐condensed [WS4]2− tetrahedra, which surround the alkali metal cations with coordination numbers of nine and eight in K2[WS4]. In Na2[WS4] ⋅ 4 H2O, the sodium cations are coordinated by two sulfide anions plus four water molecules, resulting in a coordination number of six. Besides crystal structure determination, infrared and single crystal Raman spectra were collected and the optical band gap of K2[WS4] was determined. [ABSTRACT FROM AUTHOR]

Sequence selective ring‐opening terpolymerisation (ROTERP) allows the design of block polymerisation cascades with three distinct mechanistic cycles. Ring‐opening polymerisation (ROP), ring‐opening copolymerisation (ROCOP) and ROTERP can be combined in cascades where the onset of the most complex process supresses the occurrence of the simpler ones. The cascades furthermore enable the incorporation of different heteroallenes between blocks. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Mn-NaHCO 3 displays an excellent catalytic performance and H 2 O promotion. • Alkali metal promotion is ascribed to high Mn3+/Mn4+ and O ads /O lat. • Water promotion is due to improved adsorption and activation of intermediates. • Alkali metal and H 2 O promotion are confirmed by experiments and DFT calculations. • Alkali metal and H 2 O enhanced the adsorption of toluene, intermediates and O 2. In this work, different alkali metal (Na or K)-doped manganese-based metal–organic framework (Mn-MOF) derivative materials were obtained from Mn-MIL-100 through ex situ posttreatment method, and their catalytic activities were studied by toluene oxidation. A series of characterization results (N 2 adsorption–desorption, X-ray absorption spectroscopy, temperature programmed O 2 desorption, etc.) showed that Na-doped Mn-MOF derivatives presented larger specific surface area, lower average manganese valence, and better adsorbed oxygen mobility, which displayed higher catalytic activity. Interestingly, both the addition of alkali metal and the introduction of water in the reaction atmosphere promoted the mineralization of toluene, as demonstrated by in situ diffuse reflectance infrared Fourier transform spectroscopy and thermal desorption-gas chromatography-mass spectrometry. Density functional theory calculations further confirmed that alkali metals and H 2 O were conducive to the adsorption of toluene, benzyl alcohol, benzaldehyde, benzoic acid and O 2. This work provides new ideas for developing high-efficiency and water-promotion Mn-based materials for VOC control. [ABSTRACT FROM AUTHOR]

In order to reveal the actual reaction behaviour and degradation mechanism of coke, chemical composition, mineral phase transformation and microstructure of coke at different locations in blast furnace were characterized. Meanwhile, the wear and compressive resistance, as well as the secondary thermal characteristic, were carried out. Results indicated that the mineral species and contents of cokes were significantly affected by alkali metal minerals adhesion and molten slag-iron corrosion. The alkali minerals and iron minerals adsorbed on the pore walls contributed to catalytic degradation of the bosh coke and tuyere coke respectively. In the upper zone of BF, the wear and compressive resistance of coke first decreased and then increased. The secondary thermal performance of BF coke was inverse with the content of alkali metal. The macropore structure of the hearth coke with the maximum graphitization disappeared to be replaced by slag and iron. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) have been identified as promising candidate materials in the field of proton conduction owing to their customizable and diverse structures. However, research on CPs based on alkali metal ions has been less advanced, and the mechanism of proton transport in these materials remains unclear. Herein, a new coordination polymer, [Na 2 (pytet)(Hdat) 2 (H 2 O) 3 ]·2H 2 O (abbreviated as Na-PyDat ) (pytet 4- = pyrene-1,3,6,8-tetrasulfonate, dat = 2-hydroxy-4,6-diamino-1,3,5-triazine), has been synthesized based on the starting materials of Na 4 pytet and 2-chloro-4,6-diamino-1,3,5-triazine, with the latter undergoing in situ transformation to dat under hydrothermal conditions. Na-PyDat is assembled from [Na-O-Na] n double strands and extends to a 3D network through multiple inter- and intrachain hydrogen bonds. Alternate current (AC) impedance analysis shows that Na-PyDat exhibits highly anisotropic single-crystal proton conduction, with a conductivity of 1.04 × 10 -4 S cm -1 at 338 K and 90% relative humidity (RH) along the [100] direction, which is 1-2 orders of magnitude higher than those along the [011] and [01̅1] directions, as well as the powder sample under identical conditions. The high proton conductivity along the a -axis direction is closely related to the continuous hydrogen bond chain. To the best of our knowledge, this is one of the few studies reporting single-crystal proton conduction in alkali metal CPs. Moreover, by mixing Na-PyDat with Nafion, the composite membrane presents an enhanced proton conductivity of 4.33 × 10 -3 S cm -1 at 338 K and 90% RH, highlighting its potential for future applications in fuel cells.

Alkali metal batteries have high energy densities required to power future devices; however, uneven metal deposition is a critical barrier to achieving long lifespans. We have developed an elegant noncryogenic transmission electron microscopy method which has facilitated the first observations of epitaxial deposition in alkali metal batteries. Using this method, we have confirmed epitaxial interactions between (002) sodium crystallite planes and (01-11) planes in zinc current collectors. Such epitaxial interactions decrease nucleation energy barriers and promote even metal growth. This study offers fresh inspiration for the development of electron microscopy techniques tailored to electron-sensitive battery materials and sets a new agenda for the development of battery technologies.

The development of graphene quantum dots (GQDs) with low toxicity, excellent dispersibility, and high photostability has led to extensive progress in bio-imaging and optical sensing applications. However, one-pot synthesis and mass production of GQDs, and tuning their photoluminescence, remains a challenge. Here we demonstrate a simple and scalable method for fabricating GQDs with high size uniformity and chemical stability, via a sequential process of inserting alkali metal into graphite (Stage I: KC8 and Stage II: KC24) and exfoliation to GQDs in a selected solvent. Structural and optical measurements were conducted, and the emitted colors of the as-prepared GQDs were blue (KC8) and yellow (KC24), respectively. The stage of graphite intercalation in the compounds played an important role in the size and thickness of the GQD. The as-prepared GQDs had clear characteristic peaks consistent with the quantum confinement effect and intrinsic/extrinsic states. Our approach will provide great potential for a wide variety of bioimaging and bioanalysis applications. [ABSTRACT FROM AUTHOR]

Clay minerals composed of Si and Al could help reduce ultrafine particulate matter (PM) formation as an additive during coal combustion while currently unacceptable high adding dosages (normally 3–5 wt.%) are required due to their inadequate capture efficiency. To find additives that could effectively reduce the formation of ultrafine PM, coal combustion with a novel nano SiO2 additive (<100 nm) was performed to evaluate its effects on reducing ultrafine PM. The generated PM10 was sampled to characterize their particle size distribution, mass yield, size-resolved composition and micromorphology. The results showed that adding a small dosage (0.6%) of nano SiO2 reduced the mass yield of ultrafine PM by 30.70%, showing a much higher ultrafine PM capture efficiency than an existing micron-sized natural clay mineral. However, its performance on different coals varied due to disparities in ash content and composition in coal. A composition analysis revealed that the Na content in the ultrafine PM was decreased after adding nano SiO2, indicating that nano SiO2 inhibited the migration of volatile alkali metals such as Na into ultrafine PM because the Na-containing mineral vapor reacted with the nano SiO2 additive particles with a large specific surface area at a high temperature and inhibited their transformation into ultrafine PM via homogenous nucleation. Changes in the element size distributions and micromorphology showed that the majority of the added nano SiO2 particles reacted or coalesced with each other and/or the minerals embedded in coal, finally growing into a larger PM. [ABSTRACT FROM AUTHOR]

In analyzing the effect of alkali metal and alkaline earth metal oxide on the properties of tellurite glass, a series of tellurite glass samples doped with alkali metals and alkaline earth metals were prepared based on the TeO 2 -WO 3 -GdF 3 glass system by melt quenching method. Through tests and comprehensive analysis, the results show that after the F− ions successfully enter the glass network, the substitution of TeO 2 by alkali and alkaline earth metals could reduce the molar volume, which means the glass becomes more compacted. The influence on the glass network is mainly shown in [TeO 3 ] and [TeO 4 ] units. Alkali metals and alkaline earth metals could increase the asymmetry of the TWG: Eu3+ glass network, shorten the critical distance, and increase luminescence intensity by 8.6 times and improve color purity to 94%. In addition, alkali metals could prolong the fluorescence lifetime, while alkaline earth metals could shorten it. Te4+ [ABSTRACT FROM AUTHOR]

Commercially available and inexpensive potassium bis(trimethylsilyl)amide (KHMDS) serves as an efficient transition metal‐free catalyst for the catalytic sp C−H silylation of several terminal alkynes including two pharmaceuticals. Overall, the presented system allows the synthesis of various attractive silylacetylenes under mild conditions, making this approach an environmentally benign and sustainable alternative to existing synthetic solutions. [ABSTRACT FROM AUTHOR]

• Na doping of middle rank coal enhances its carbon capture capacity. • The binding energy required for doping is proportional to the atomic radius. • The highest adsorption for CO 2 (5.934 mmol/g) was found in the Na-CYM system. • The diffusion coefficient of CO 2 is minimized in the Li-coal system. Coal-based adsorbents show promise for advancing Direct Air Capture (DAC) technology as support for carbon capture grows. Doping coal with alkali metals (Li, Na, K) enhances gas molecule interactions and improves adsorption capacity. Using Density Functional Theory (DFT) and Grand Canonical Monte Carlo (GCMC), the study investigated the adsorption and diffusion performances of CO 2 , CH 4 , and N 2 in modified coal. The results showed that binding energy increases with the increasing radius of the dopant atoms, with K-SM requiring the most energy (31.236 eV). The adsorption capacity followed the order: Na-coal > Li-coal > K-coal > Undoped-coal, with Na-coal achieving the highest CO 2 adsorption (5.934 mmol/g). After alkali metal doping, the adsorption amounts of CO 2 , CH 4 , and N 2 increased by 26.80 %, 43.29 %, and 56.60 %, respectively, with the Na-doped middle-rank coal showing an average increase of 32.33 % in CO 2 adsorption. The diffusion coefficient of Na-coal was lower than that of Li-coal and K-coal, with CO 2 having the smallest diffusion coefficient (1.627 × 10-8 m2/s). Overall, alkali metal doping significantly enhances the adsorption and stability for CO 2 , CH 4 , and N 2 , particularly with Na doping in middle-rank coal, providing insights for developing high-performance CO 2 adsorbent. [ABSTRACT FROM AUTHOR]

Two polymorphs of the title tetrakis-substituted pyrazine carboxylic acid, 3,3′,3′′,3′′′-{[pyrazine-2,3,5,6-tetrayltetrakis(methylene))tetrakis(sulfanediyl]}tetrapropionic acid, C20H28N2O8S4, (H4L1), have been obtained, H4L1_A and H4L1_B. Each structure crystallized with half a molecule in the asymmetric unit of a triclinic P\overline{1} unit cell. The whole molecules are generated by inversion symmetry, with the pyrazine rings being located about inversion centers. The crystals of H4L1_B were of poor quality, but the X-ray diffraction analysis does show the change in conformation of the –CH2—S—CH2—CH2– side chains compared to those in polymorph H4L1_A. In the crystal of H4L1_A, molecules are linked by two pairs of O—H...O hydrogen bonds, enclosing R22(8) ring motifs forming layers parallel to plane (100), which are linked by C—H...O hydrogen bonds to form a supramolecular framework. In the crystal of H4L1_B, molecules are also linked by two pairs of O—H...O hydrogen bonds enclosing R22(8) ring motifs, however here, chains are formed propagating in the [001] direction and stacking up the a-axis. Reaction of H4L1 with Hg(NO3)2 in the presence of a potassium acetate buffer did not produce the expected binuclear complex, instead crystals of a potassium–organic framework were obtained, poly[(μ-3-{[(3,5,6-tris{[(2-carboxyethyl)sulfanyl]methyl}pyrazin-2-yl)methyl]sulfanyl}propanoato)potassium], [K(C20H27N2O8S4)]n (KH3L1). The organic mono-anion possesses inversion symmetry with the pyrazine ring being located about an inversion center. A carboxy H atom is disordered by symmetry and the charge is compensated for by a potassium ion. A similar reaction with Zn(NO3)2 resulted in the formation of crystals of a dipotassium-organic framework, poly[(μ-3,3′-{[(3,6-bis{[(2-carboxyethyl)sulfanyl]methyl}pyrazine-2,5-diyl)bis(methylene)]bis(sulfanediyl)}dipropionato)dipotassium], [K2(C20H26N2O8S4)]n (K2H2L1). Here, the organic di-anion possesses inversion symmetry with the pyrazine ring being located about an inversion center. Two symmetry-related acid groups are deprotonated and the charges are compensated for by two potassium ions.

The electronic property of a catalyst is crucial to the generation of key reaction intermediates for targeted synthesis. Herein, we reported a strategy by modifying iron catalysts with sulfate and alkali metal (Li, Na, or K) to regulate the electronic property and optimize the reaction pathways for CO 2 hydrogenation to higher alcohols. The characterizations demonstrated the influencing relationship between the electronic property of iron catalysts and the catalytic capabilities for CO dissociation, non-dissociated CO activation and catalytic hydrogenation, which were critical to selective synthesis of higher alcohols. Na-S modification was proven more effective to balance the multiple capabilities required for higher alcohols synthesis and the NaS-Fe catalyst gave a higher C 2+ OH yield in CO 2 hydrogenation. DFT calculations further validated the advantage of Na-S modification from the aspects of CO adsorption and C−C coupling. This strategy provides more flexibility in site regulation and applies to catalyst design for many reactions. [Display omitted] • The relationship between electronic property and catalytic capability was studied. • Alkali metal and sulfate act as dual-promoter to regulate the electronic property. • A balance between alkyl, *CO and *H species is required for alcohol formation. • Moderate electronic modification optimizes the generation of key intermediates. • Higher alcohols synthesis is favored on Na-S modified iron catalyst. [ABSTRACT FROM AUTHOR]

A variety of group 1 organometallics complexes were synthesized using two iminophosphoranomethanide ligands with differing steric properties. An in-depth structural and spectroscopic analysis was carried out, together with DFT analysis, to probe the nature of the metal-carbon interactions. [Display omitted] Herein we report the synthesis of three sets of alkali metal complexes with the iminophosphoranomethanide ligands {CH(SiMe 3)P(Ph) 2 NSiMe 3 }− (TMSNPC-H) and {CH(SiMe 2 t Bu)P(Ph) 2 NSiMe 3 }− (TBDMSNPC-H), the latter of which is first reported here. The compounds of general formula [M(RNPC-H)] (3-M and 4-M ; M = Li, Na, K) were obtained via a protonolysis reaction between an alkyl reagent (n -butyllithium, benzylsodium, or benzylpotassium) and the proligand. All resulting compounds were characterized by multinuclear NMR, IR spectroscopy, elemental analysis and single crystal X-ray diffraction. We also attempted to prepare the separated ion pairs of [M(TMSNPC-H)] with the matched crown ethers, and obtained the 'ate' complexes [Li(12-crown-4) 2 ]+[Li(TMSNPC-H) 2 ]− (5-Li) and [Na(15-crown-5) 2 ]+[Na(TMSNPC-H) 2 ]− (5-Na), the coordination polymer [{K(18-crown-6) 2 }{K(TMSNPC-H)(18-crown-6)}(TMSNPC-H)] ∞ (6) and separate ion pair complex [K(15-crown-5) 2 ]+[TMSNPC-H]− (7). 5-Li is an unusual lithium-lithiate crown ether species, whilst 5-Na represents the first example of a sodium-sodiate crown-ether complex. [ABSTRACT FROM AUTHOR]

• SMSI effect plays an important role in CO oxidation. • The alkali metal Na can act as the SMSI effect in Pt-0.5P&W/TiO 2. • Electrostatic force is the reason for the increase of reactive oxygen species on catalyst surface. The dopant WO 3 of the catalyst Pt-0.5P&W/TiO 2 enhanced the SO 2 resistance of the catalyst for CO oxidation in sintering waste gas, but it also had an impact on strong metal-support interactions (SMSI), which decreased the CO catalytic activity. Adding alkali metal Na to Pt-0.5P&W/TiO 2 can effectively improve the CO catalytic performance. The Pt–O–Na bond replaced the Pt–O–Ti bond, allowing Na to act as an electron and structure promoter instead of TiO 2 to contribute the electronic and synergistic effects in catalysis. XPS and EPR date indicated that the positively charged group centered on Pt adsorbed hydroxyl groups by electrostatic interaction, which co-acted with Na to form Pt-O x (OH) y Na. In situ infrared data indicated that Na promoted the electron density on the Pt surface leading to the disproportionation of CO on the Pt surface to produce inactive C*. The production of C* facilitated the adsorption and activation of O 2 by blocking the single-layer adsorption of CO on Pt. The active oxygen species adsorbed on the catalyst surface increased the CO activity of the catalyst. In sulfur-containing flue gas conditions, SO 2 reacted with Na around Pt to generate sodium sulfate, which enhanced the local acidity of the active site and the sulfur resistance of the catalyst. [ABSTRACT FROM AUTHOR]

Previous studies have shown that alkali metals catalyse the pyrolysis and gasification processes of biomass. However, whether alkali metals have the same catalytic effect on the reduction reaction of biochar with iron oxide has not been investigated. In this article, the effect of alkali metals on the reduction behaviour of biochar with iron oxide was investigated. It was shown that adding alkali metal carbonate could increase the reaction rate of CSC reduction stages 1 and 2, but it played an inhibitory role for the first and middle periods of stage 3. Moreover, adding alkali metals resulted in higher total CO2 gas production and reduced total CO gas production for the reduction reaction. The GB1 model was the best mechanistic model for stages 1 and 2 of the CSC-2K and CSC-2Na reduction reactions, while the C1 model was the best mechanistic model for stage 3. [ABSTRACT FROM AUTHOR]

Alkali metal vapor was applied as sensitive frequency-conversion photodetectors, however, their application was limited by their natural narrow (∼100 MHz) sensing frequency range. Here, Cs–Xe excimer is used to break this limitation. Demonstration of Cs–Xe frequency up-conversion photodetector is given. Using excimer transition, 550–552 nm light is converted to 541 nm fluorescence, this conversion wavelength band is much larger than a typical atom energy level transition. The frequency up-conversion background is mainly energy pooling fluorescence, which varies with Cs 6P 3/2 state number density on roughly a cubic function. Atom collision generated Cs 12D J , 9F J levels are measured and discussed. By switching excimer transitions selected, e.g. using Cs nP J (n = 7, 8, ...) related upward excimer transitions, it is possible to detect light with other wavelength from infrared to terahertz band. The concept in this work may get application in photon detection with high sensitivity. • Cesium xenon excimer realizes broadband thresholdless photon frequency conversion. • Excimer spectra are compared with cesium atom-only situation to reveal kinetics. • Noise level in the photon frequency conversion is studied and management is given. [ABSTRACT FROM AUTHOR]

A straightforward and efficient protocol to promote the metalation/anionic Fries rearrangements of O‐aryl carbamates, using for the first time a lithium amide as metalating agent under aerobic/ambient‐friendly reaction conditions, is reported. This approach enables the sustainable preparation of salicylamide derivatives with high levels of chemoselectivity within ultrafast reaction times, working at room temperature in the presence of air/moisture, and using environmentally responsible cyclopentyl methyl ether as a solvent. Furthermore, the regioselective manipulation of O‐2‐tolyl carbamates has been accomplished using interchangeably alkyllithiums or lithium amides, with an unexpected beneficial contribution from the employment of biorenewable protic eutectic mixtures as non‐innocent reaction media. [ABSTRACT FROM AUTHOR]

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The NO heterogeneous reduction by char is one of the most prominent options to control NOx emissions from coal-fired power plants. Experiments on the char-NO heterogeneous reaction were carried out in an electrically heated fixed-bed reactor to investigate the effect of temperature, type of char, pretreatment method, additives and reaction atmosphere on the NO reduction capacity of char. The results showed that temperature plays a crucial role in the NO reduction by different char. The kinetic analysis showed that char-NO heterogeneous reaction is controlled by chemical kinetic below Tt and by diffusion kinetic above Tt. The value of transition temperature Tt depends on the types of char and ranges from 600 °C to 800 °C. The synergistic effect of specific surface area, mineral abundance and reactivity combine to result in the reduction efficiencies of different char. Oxygen has a promoting effect on the char-NO heterogeneous reaction, and the oxygen content of the promoting peak moves to low oxygen content with increasing temperature. At 1050 °C, the denitrification efficiency at 0.25% O2 content is 12.7% higher than that under oxygen-free conditions. At high temperatures, the promotion of the char-NO heterogeneous reaction by CO and the inhibition of the reaction by CH4 were more obvious. [ABSTRACT FROM AUTHOR]

Molybdenum carbide (Mo2C) is a promising and low-cost catalyst for the reverse water−gas shift (RWGS) reaction. Doping the Mo2C surface with alkali metals can improve the activity of CO2 conversion, but the effect of these metals on CO2 conversion to CO remains poorly understood. In this study, the energies of CO2 dissociation and CO desorption on the Mo2C surface in the presence of different alkali metals (Na, K, Rb, and Cs) are calculated using density functional theory (DFT). Alkali metal doping results in increasing electron density on the Mo atoms and promotes the adsorption and activation of CO2 on Mo2C; the dissociation barrier of CO2 is decreased from 12.51 on Mo2C surfaces to 9.51–11.21 Kcal/mol on alkali metal-modified Mo2C surfaces. Energetic and electronic analyses reveal that although the alkali metals directly bond with oxygen atoms of the oxides, the reduction in the energy of CO2 dissociation can be attributed to the increased interaction between CO/O fragments and Mo in the transition states. The abilities of four alkali metals (Na, K, Rb, and Cs) to promote CO2 dissociation increase in the order Na (11.21 Kcal/mol) < Rb (10.54 Kcal/mol) < Cs (10.41 Kcal/mol) < K (9.51 Kcal/mol). Through electronic analysis, it is found that the increased electron density on the Mo atoms is a result of the alkali metal, and a greater negative charge on Mo results in a lower energy barrier for CO2 dissociation. [ABSTRACT FROM AUTHOR]

Summary: A novel Cu/Na‐CdS optoelectronic photodetector is prepared and applied for detecting the light in the UV and Vis regions with high efficiency. First, CdS and M‐CdS nanomaterials (M = Li, Na, or Cs) are prepared using the hydrothermal method at 180°C for 24 hours. The prepared nanomaterials have crystalline structures that are confirmed through X‐ray diffraction analyses. Na‐CdS has the optimum structure with a crystalline size of 17.5 nm and porous structure looks small grass. Moreover, Na‐CdS has the optimum optical absorbance and bandgap of 1.78 eV. Na‐CdS nanomaterial is applied as optoelectronic material for light detection under different intensities and wavelengths. The device detected the light in the UV and Vis regions with high efficiency. The current density (Jph) values increased highly in light in compared with dark conditions, in which Jph changed from 20 μA cm−2 to 2.88 mA cm−2 in dark and light, respectively. The detectivity (D) and photoresponsivity (R) were 1.5 × 1010 Jones and 38 mA W−1, respectively. Also, the external quantum efficiency (EQE) was 12% at 390 nm and 100 mW cm−2. The high properties of Na‐CdS optoelectronic qualify it to be applicable in the industrial field incorporated with high technology devices such as cameras and spacecraft. [ABSTRACT FROM AUTHOR]

Fossil fuels are limited and unsafe for environment due to carbon emission. To minimize the dependence on fossil fuel hydrogen has been accepted as a supreme energy carrier. But the challenge of new hydrogen economy is to find appropriate materials that can store hydrogen with intermediate adsorption energy. Hence fullerene (C60) has been investigated intensively around the world for its ability to adsorb hydrogen. In this paper we present results of density functional theory (DFT) calculations of the adsorption of hydrogen molecules on alkali metal (Li, Na, K) doped fullerene (C60). Adsorption energy, charge distribution, photon absorption, global indices, optical band gap energy etc. have been investigated for the better understanding of doped and undoped fullerene. All the parameters have been calculated by Gaussian 09 simulation package using density functional theory (DFT) with 6-31G/UB3LYP level of theory.The adsorption energies of molecular hydrogen on alkali metal doped fullerene is negative, i.e., exothermic. The attractive interaction between the surface dipole and the dipole of polarized H2may contribute this adsorption energy. From this result it can be expected that alkali metal-decorated fullerene could be considered as a potential high-capacity hydrogen storage medium.

Iron ore sintering is a process in which iron ore powder, flux, iron-bearing dust, solid fuel (such as coke powder), and return fines are mixed in a certain proportion, granulated, and then processed into agglomerates by high-temperature generated by solid-fuel combustion, which is an important process prior to blast furnace ironmaking. The iron ore sintering process is an important emitter of atmospheric particles in which alkali metal elements in a sinter bed contribute to the formation of fine particles during combustion, aggravating particulate emissions. Using biomass materials such as charcoal to replace coke in the sintering process can significantly alleviate the emission of both greenhouse gases and pollutants. However, owing to the high content of alkali metals in biomass and their poor combustion characteristics, alkali-metal-related problems inevitably arise. In this study, a small sintering experiment was conducted in a volatilization condensation test facility and analyses were performed based on data obtained by X-ray fluorescence spectroscopy, scanning electron microscopy energy dispersive spectrometer, and inductively coupled plasma-atomic emission spectrometry followed by thermodynamic simulation. The purpose of these analyses was to investigate the laws associated with alkali metal migration and enrichment, removal rate of alkali metal elements, and influence of technological measures on removal process in iron ore sintering using charcoal and coke as fuel with iron-bearing dust added. The results show that K is easier to remove than Na, and the alkali compounds volatilized into a flue gas mainly contain KCl with small amount of NaCl. With the same fuel mass fraction the removal rate of alkali metal in the sintering process using charcoal as fuel is less than that using coke. As the alkali metal compounds in the downstream flue gas migrate, they collide with the raw material particles because of the inertial effect. In addition, owing to the low temperature of the raw materials in the low bed, alkali metal compounds tend to condense and deposit on the particles’ surface. During the sintering process, a large number of alkali metal compounds discharged into the waste gas are trapped and absorbed by the low bed, and the alkali metal chloride accumulated in the low bed promotes the removal of chloride from the alkali metal. With the addition of CaCl2, the removal rate of K and Na when using charcoal as fuel is higher than that using coke. Accordingly, the content of K and Na in sintering products with charcoal as fuel is lower than that using coke. The use of biomass as fuel in iron ore sintering in combination with chlorine removal process is feasible and has good prospects.

In the DEMO-Oriented NEutron Source (DONES) facility, it is expected to use a considerable amount of lithium at an average temperature higher than 300 °C. It is well known that lithium can produce exothermic reactions with several media, generating corrosive and toxic (upon burning) reaction products and with the potential risk of mobilizing radionuclides in little amounts. As a result, lithium represents a hazardous material which must be safely handled under normal operation and, especially, potential accident conditions which involve lithium spills and radioactive releases.Although the burning behavior of lithium has been studied for several decades, there is still a wide dispersion of data regarding its actual ignition temperature. Generally, measurements of the spontaneous or induced ignition temperature of a leakage of molten lithium, pool/spray type, depend on several factors such as metal purity, gas atmosphere composition and relative humidity, sample size or geometrical aspects, and even different treatments, apparatus, and techniques used.A dedicated experimental facility, called “LiFIRE”, is currently under development at the National Fusion Laboratory of CIEMAT with the purpose to quantitatively support the DONES safety analysis on the fire risk in case of lithium leakages, based on the Defense-in-Depth principle, i.e. prevention, detection and mitigation.

[Display omitted] Realizing the simultaneous adsorption and activation of O 2 and reactants over supported noble metal catalysts is crucial for the oxidation of organic hydrocarbons. Herein, we report a facile one-step ethylene glycol reduction method to synthesize difunctional Au(OH)K x sites, which were anchored on a hierarchical hollow MFI support and adopted for acetone decomposition. The alkali ion-associated adjacent surface hydroxyl groups were coordinated with Au nanoparticles, resulting in partially oxidized Au1+ sites with improved dispersion. The results obtained from exclusive ex situ and in situ experiments illustrated that the proper content of K and hydroxyl groups significantly enhanced the adsorption of surface O 2 and acetone molecules around the Au sites simultaneously, whereas the excess K species inhibited the catalytic performance by blocking the pore structure and decreasing the acidity of catalysts. The Au(OH)K 0.7 /h-MFI catalyst exhibited the highest efficiency for acetone oxidation, over which 1500 ppm acetone can be completely oxidized at just 280 °C with an extremely low activation energy of 32.5 kJ mol−1. The carbonate species were detected as the main intermediates during acetone decomposition over the difunctional Au(OH)K x sites through a Langmuir − Hinshelwood (L − H) mechanism. This finding paves the way for designing and constructing efficient functional active sites for the complete oxidation of hydrocarbons. [ABSTRACT FROM AUTHOR]