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Here, the chemical modification of Ziziphus jujuba stones (ZJS) treated with ortho-phosphoric acid (ZJS-H3PO4) is investigated to enhance its adsorption properties for organic dyes. The physicochemical properties of ZJS-H3PO4 reveal increased porosity (87.29%), slightly higher bulk density (0.034 g mL−1), and enhanced acidity (31.42 m eq g g−1) compared to untreated ZJS. XRF analysis confirms the successful incorporation of orthophosphoric acid during treatment due to a significant increase in phosphorus content. The maximum adsorption capacity of methylene blue on ZJS-H3PO4 is found to be 179.83 mg g−1, demonstrating its efficacy as a potential adsorbent for organic dyes. These findings suggest that modifying ZJS with orthophosphoric acid could be a promising strategy to enhance its adsorption performance in various environmental applications. Furthermore, Gaussian process regression (GPR) is employed to model MB adsorption by ZJS-H3PO4. Optimization of the GPR model involves evaluating different kernel functions and meticulously adjusting parameters to maximize its ability to capture complex relationships in the data. The obtained GPR model demonstrates remarkable performance with high correlation coefficients (R) and low root mean square errors (RMSEs) across all study phases. Model validation is performed through residual analysis, confirming its effectiveness and accuracy in predicting MB adsorption. Finally, a user-friendly interface is developed to facilitate the usage of the GPR model in future applications, representing a significant advancement in environmental process modeling and ecosystem management. [ABSTRACT FROM AUTHOR]

[Display omitted] • LLE data for the quaternary systems of H 2 O+H 3 PO 4 + DIPE+TBP/MIBK. • Study of the effect of TBP and MIBK on the three-phase zone. • Three-phase zone disappeared after the addition of 0.206 of TBP and 0.583 of MIBK. • The mixed solvent (TBP+DIPE) is the best-performing solvent. • The mixed solvent (0.3TBP+0.7DIPE) has the potential to enhance H 3 PO 4 extraction. The three-liquid-phase formation in the ternary system of water + phosphoric acid + diisopropyl ether (DIPE) makes the phosphoric acid extraction only effective for acid mass fractions above 0.69. To avoid the undesirable formation of the third phase and enhance acid extraction, particularly at low concentrations, two phase modifiers, methyl isobutyl ketone (MIBK) and tributyl phosphate (TBP), were systematically studied. In order to quantify the synergetic effect of the mixed solvents of DIPE+TBP and DIPE+MIBK, the liquid–liquid equilibria for the quaternary systems of H 2 O+H 3 PO 4 + DIPE+TBP and H 2 O+H 3 PO 4 + DIPE+MIBK were fully established for different DIPE/phase modifier (TBP or MIBK) mass ratios (90/10, 70/30, 50/50, and 20/80) at 298.2 K under atmospheric pressure using the cloud point and Othmer graphical method. Othmer-Tobias and Hand correlations were used to fit the tie-line data and assess its consistency. In addition, the behavior of the three-phase zone was also studied as a function of the phase modifiers content. Separation factor (S) and acid distribution (D 2) were used to identify the most effective solvent with the potential to enhance phosphoric acid extraction from aqueous solutions. [ABSTRACT FROM AUTHOR]

To analyze the effects of binder content on the performance and durability of high-temperature PEMFC, we investigate detailed distribution of PTFE-binder whose content ranges from 7.7 to 35.1 wt% on Pt/C models in the presence of H 3 PO 4 at room (298.15 K) and operating (433.15 K) temperatures. Pair correlation function (PCF) analysis shows that the distribution of H 3 PO 4 on the Pt particle significantly changes as a function of PTFE-binder content beyond 20.0 wt% at 298.15 K due to the onset of Pt particle coverage by PTFE-binder starts. However, under 433.15 K, the higher kinetic energy enables more H 3 PO 4 to access the Pt surface to maintain greater contact. In case of H 3 PO 4 on the carbon surface, the intensities of PCF significantly decrease with increasing PTFE-binder levels up to 20.0 wt% at both 298.15 and 433.15 K as the carbon surface becomes occupied by the PTFE-binder up to ~20.0 wt%. The surface coverage analysis also shows that the H 3 PO 4 coverage on Pt surface decreases from 72.4 to 30.5% with increasing PTFE-binder content from 7.7 to 35.1 wt% at 298.15 K. However, the H 3 PO 4 coverage on Pt surface is significantly higher at 433.15 K in comparison to that at 298.15 K because H 3 PO 4 could still permeate the PTFE-binder to contact the Pt particle due to the favorable interactions. Three-phase interfacial configurations of Pt/C catalyst layer as increasing binder contents. [Display omitted] • Detailed molecular distributions were investigated using full atomistic molecular dynamics. • Force fields for the van der Waals parameters between H 3 PO 4 and Pt particles were developed. • H 3 PO 4 on Pt particle significantly changes as binder content beyond 20.0 wt% at 298.15 K. • Under 433.15 K, the higher kinetic energy enables more H 3 PO 4 to access the Pt surface. • Carbon surface becomes occupied by the binder up to ~20.0 wt% at both 298.15 and 433.15 K. [ABSTRACT FROM AUTHOR]

A highly shape‐selective and relatively long‐lifetime HZSM‐5‐based catalyst (Zn‐2P/HZSM‐5) was prepared by chemical modification with both ZnSiF6·6H2O and H3PO4 solution. The phosphoric acid modification could effectively modulate the Brønsted acid strength of the HZSM‐5 catalyst, which promotes the oligomerization, alkylation, cyclization, and hydrogen transfer reactions. The introduction of Zn‐Lewis acid sites significantly improved the dehydroaromatization of higher olefins. All of these were very beneficial for the generation of BTX (i.e. benzene, toluene, and xylene) hydrocarbons in aromatization of methanol. The coke amount and the average rate of coke formation decreased over the Zn‐2P/HZSM‐5 catalysts, which may largely be ascribed to its lower strong acid sites and lower outer surface acidity. The catalytic performance of methanol aromatization showed that the Zn‐2P/HZSM‐5 catalyst exhibited the highest BTX selectivity of about 46.76% and the longest catalytic lifetime of about 498 h at T = 400 °C, P = 0.1 MPa, and weight hourly space velocity = 0.7 h−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • BPSBC was the first time synthesized to efficiently remove environmental concentration SMX. • Pyrolysis and ball milling parameters were optimized to prepare modified SBC. • PSBC showed higher adsorption capacity than those of ASBC and NASBC. • Physical and chemical forces simultaneously contributed to SMX adsorption by BPSBC. • BPSBC exhibited satisfactory stability in a wide pH range and was easily regenerated. Efficiently eliminating environmental concentration sulfamethoxazole (SMX) from water has become a great challenge because its undesirable removal efficiencies/rates by the present sewage treatment technologies. In this study, various pyrolysis temperatures (400–700 °C), ball milling parameters (speed (300–700 rpm) and time (30–120 min)) and acids (CH 3 COOH, H 3 PO 4 and HNO 3) hydrothermal activation were studied to optimize the preparation of modified sludge biochar (SBC) with the greater adsorption capacity. As expected, ball milling and H 3 PO 4 hydrothermally co-functionalized SBC (BPSBC) showed the optimum adsorption performance for SMX, and its maximum adsorption capacity (4.61 × 104 μg/g) calculated from Langmuir model was 6.30 times that of SBC. The adsorption behaviors and mechanism were investigated by kinetics, isotherms model fitting, thermodynamics, characterization, and density functionalization theory (DFT) calculation etc. Pore filling, π-π conjugation, H-bonding and P-O complexation were proved to be the main contributors to SMX adsorption by BPSBC. BPSBC showed the favorable sustainable adsorption performance for SMX by NaOH regeneration and stability over a broad pH value with the low leaching risk of phosphorus. This work developed a promising adsorbent of BPSBC for environmental concentration SMX removal, in addition to that the resource utilization of sludge was simultaneously achieved. [ABSTRACT FROM AUTHOR]

Ethanol is an important bulk chemical with diverse applications. Biomass‐derived ethanol is traditionally produced by fermentation. Direct cellulose conversion to ethanol by chemocatalysis is particularly promising but remains a great challenge. Herein, a one‐pot hydrogenolysis of cellulose into ethanol was developed by using graphene‐layers‐encapsulated nickel (Ni@C) catalysts with the aid of H3PO4 in water. The cellulose was hydrolyzed into glucose, which was activated by forming cyclic di‐ester bonds between the OH groups of H3PO4 and glucose, promoting ethanol formation under the synergistic hydrogenation of Ni@C. A 69.1 % yield of ethanol (carbon mole basis) was obtained, which is comparable to the theoretical value achieved by glucose fermentation. An ethanol concentration of up to 8.9 wt % was obtained at an increased cellulose concentration. This work demonstrates a chemocatalytic approach for the high‐yield production of ethanol from renewable cellulosic biomass at high concentration. [ABSTRACT FROM AUTHOR]

Tunisian industrial phosphoric acid H3PO4 was supported on silica gel SiO2 (SIPA) to catalyze the hydrolysis reaction of aqueous alkaline sodium borohydride (NaBH4). The SiO2 was produced from purified quartz sand using alkali fusion-acidification chemical process. The BET surface area results indicate that the prepared silica gel could reach a specific surface area up to 585 m2/g. The addition of PO3H2 functional groups resulted in an increase of surface acidity of SiO2 catalyst as shown by FT-IR and DTA-DTG spectra. The total acidity of SIPA catalyst was determined by titration to be 2.8 mmol H+/g. SEM/EDS maps reveal the distribution of heavy metals on the silica surface. The effect of supported PO3H2 functional groups and heavy metals on the NaBH4 hydrolysis reaction was studied for different ratios of SIPA catalyst to NaBH4. The sample 12SIPA/NaBH4 leads to a very high hydrogen generation rate (up to 90%). The activation energy of hydrogen generation by NaBH4 hydrolysis was 25.7 kJ mol−1. [ABSTRACT FROM AUTHOR]

The SEM and EDS study results of coatings obtained on titanium by Plasma Electrolytic Oxidation (PEO) in the electrolytes containing of 600 g copper nitrate in 1 liter of concentrated phosphoric acid at 450 V for 1 and 3 minutes, are presented. The obtained coatings are porous and consist mainly of phosphorus within titanium and copper. It was found that the time of PEO oxidation has impact on the chemical composition of the coatings. The longer time of PEO treatment, the higher amount of copper inside coating. The PEO oxidation of titanium for 1 minute has resulted in the creation of coating, on which 3 phases where found, which contained up to 13.4 wt% (9 at%) of copper inside the phosphate structure. In case of 1 minute PEO treatment of titanium, the 2 phases were found, which contained up to 13 wt% (8 at%) of copper inside the phosphate structure. The copper-tophosphorus ratios after 1 minute processing belong to the range from 0.28 by wt% (0.14 by at%) to 0.47 by wt% (0.23 by at%), while after 3 minutes the same ratios belong to the range from 0.27 by wt% (0.13 by at%) to 0.35 by wt% (0.17 by at%). In summary, it should be stated that the higher amounts of phosphorus and copper were recorded on titanium after PEO oxidation for 3 minutes than these after 1 minute. [ABSTRACT FROM AUTHOR]

In this study, activated carbons were produced from wild chestnut shells by means of chemical activation with H3PO4 in a N2 atmosphere and their characteristics were investigated. The chemical activation process was conducted at different impregation ratio (1:1-1:4) and final carbonisation tempreratures (500-700°C). The influence of the activation parameters, such as carbonisation temperature and the imperagnation ratio, was investigated. The characterisation of the activated carbons has been identified with nitrogen adsorption (BET), X-ray diffraction (XRD), Fourier transform electron infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). While using the 1:4 impregnation ratios at the carbonisation temperature of 600°C, the specific surface area of the carbon is as high as 982 m²/g. Experiments were carried out at different carbonisation temperatures and impregnation ratios, which had significant effects on the pore structure and surface area of carbon. [ABSTRACT FROM AUTHOR]

Mesoporous bioactive glass (MBG) was obtained by the evaporation-induced self-assembly method which uses H3PO4 as catalyst and nonionic block copolymer (EO20PO70EO20, P123) as templates, respectively. Its average pore diameter, specific area and pore volume were 3.6 nm, 476.7 m²g- 1 and 0.49 cm³g- 1. The structure and performance were characterized by small-angle X-ray diffraction (SAXRD), nitrogen adsorption-desorption isotherms and transmission electron micrographs (TEM). The results demonstrated that using H3PO4 as catalyst is useful to prepare MBG with larger surface area and highly ordered mesopore. In vitro bioactivity test suggested that this MBG exhibited an excellent formation of hydroxyl-carbonated apatite layer. [ABSTRACT FROM AUTHOR]

Abstract: The effects of H3PO4 on the compressive strength of block CaO, phase composition and morphology of calcined carbide slag were investigated. The results indicated that block CaO could be prepared from carbide slag through molding and calcination. H3PO4 had a promotive effect on the compressive strength of block CaO, which reached the maximum value at 3.2MPa with a H3PO4 content of 4%. Meanwhile, the compressive strength of block CaO increased with an increase of molding pressure. Moreover, the P-containing phase in carbide slag shifted from hydro-phosphate to phosphate after calcination. The close connection on the surface of particles was enhanced by the formation of phosphate. [Copyright &y& Elsevier]

Abstract: A new, simple and accurate method is introduced for determining H2CO3 ⁎ alkalinity in fresh waters dominated by the carbonate weak-acid system. The method relies on a single H3PO4 dosage and two pH readings (acidic pH value target: pH∼4.0). The computation algorithm is based on the concept that the overall alkalinity mass of a solution does not change upon the addition of a non-proton-accepting species. The accuracy of the new method was assessed batch-wise with both synthetic and actual tap waters and the results were compared to those obtained from two widely used alkalinity analysis methods (titration to pH∼4.5 and the Gran titration method). The experimental results, which were deliberately obtained with simple laboratory equipment (glass buret, general-purpose pH electrode, magnetic stirrer) proved the method to be as accurate as the conventional methods at a wide range of alkalinity values (20–400mgL−1 as CaCO3). Analysis of the relative error attained in the proposed method as a function of the target (acidic) pH showed that at the range 4.0

Abstract: Highly mesoporous activated carbons (ACs) with a mesopore fraction ranging from 42 to 73% were obtained by activation of rice straw (RS) with ortho-phosphoric acid (PA). Due to such a high mesoporosity, these ACs can be successfully used for pollutant removal in aqueous phase. The ACs were prepared at activation temperatures (T) ranging from 350 to 500°C, using PA to RS weight ratios (R) from 0 to 1.6 and activation times from 0 to 2h. They were characterised by nitrogen adsorption at −196°C, SEM-EDX, and methylene blue adsorption. RS is a very heterogeneous material with a variable content of mineral matter: using the product of activated carbon yield multiplied by surface area (C × S BET ) as the performance criterion, the best AC was produced at T =450°C and R ≥1. These conditions lead to S BET higher than 500m2 g−1 and a C × S BET around 270m2 g−1. [Copyright &y& Elsevier]

Abstract: Polyaniline (PANI)-chemically coated the electrode of quartz-crystal microbalance (QCM) has been developed for the determination of phosphoric acid (H3PO4) in the liquid phase. The sensing mechanism is based on the fact that the QCM devices produce a change in the oscillating frequency when the PANI coating the electrode of QCM interacts with different concentration of the acid. This was made during the subsequent redoping–dedoping processes of the PANI film in acid and ammonia solutions, respectively. Also, this was made during the successive redoping in different acid solutions. The QCM sensor demonstrated a rapid response to the acid with an excellent reversibility. A linear response of the sensor for different concentrations of H3PO4 was found in region of ⩽1M. The conductivity at different concentration of the acid was also determined. Finally, pH dependence on the electronic absorption of PANI phosphate film was studied which indicates that the film can be used as a sensor over a wider pH range of 3–12. This is in comparison to a PANI-sulphate film which shows limited pH absorption dependence (5–8). [Copyright &y& Elsevier]

Poly(aniline) was synthesized by electrochemical oxidation from phosphoric acid at concentrations from 0.1 mol/L up to 7 mol/L in an electrochemical quartz crystal microbalance (EQCM) equipped cell in a three-electrode configuration. Deposition processes were monitored by a recently introduced fast impedance-scanning quartz crystal microbalance to determine the optimal concentration for most effective electropolymerization parameters. [ABSTRACT FROM AUTHOR]

The preparation of activated carbons (ACs) from the thermal decomposition of mixtures of orthophosphoric acid (PA) and either as-received softwood Kraft lignin, KL, or demineralised one, KLd, has been investigated. Activation with PA has been studied for a PA/lignin ratio of 1 (dry ash-free basis) and 1h carbonisation time at final temperatures of 400, 500 and 600°C. The yield, surface area, porosity, surface chemistry and methylene blue adsorption capacity have been determined. All ACs were found to be essentially microporous, with surface areas higher than 800m2/g and a maximum value of nearly 1200m2/g for the carbon prepared at 600°C from KL. In order to study the influence of temperature on the properties of the ACs prepared from KL and KLd, the latter precursors were analysed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). We have concluded that the very different characteristics of the ACs obtained from KL and KLd are due to the presence or not of mineral matter during carbonisation, but mainly to the demineralisation process itself, which produces polymerisation of the raw lignin. Methylene blue adsorption was found to be higher for ACs prepared from KL, mainly because of their higher ash and sulphur contents. [Copyright &y& Elsevier]

Upon adding biomass under the action of water, heat, and catalyst, a wonderful chemical reaction occurs to obtain the ethanol. With the aid of Ni@C catalyst and H SB 3 sb PO SB 4 sb , cellulose is directly converted into ethanol with a high yield of 69.1 %, and an ethanol concentration up to 89 g L SP -1 sp . [Extracted from the article]

Dry powder fire-extinguishing agent is one of Halon substitutes due to its superior fire-extinguishing performance, non-toxicity, and environmental friendliness. As one of the most widely used dry powders, ABC dry powder has attracted wide attention. Understanding its reaction mechanism is important to the design of more efficient compound dry powder based on it. When ABC dry powder was applied to the flame, ammonium dihydrogen phosphate (the main fire-extinguishing component of ABC dry powder) would rapidly decompose into phosphoric acid (H3PO4) and ammonia. Therefore, in order to figure out the chemical reaction mechanism of ABC dry powder and active radicals, the main focus of this paper is on the H3PO4. Analysis of the electrostatic potential on van der Waals surface of H3PO4 was carried out. Besides, detailed theoretical investigation has been performed on the mechanism, kinetics, and thermochemistry of the reactions of H3PO4 with H, OH, and CH3 radicals and further decomposition of H3PO4 using M06-2X/6-311G(d,p)//CCSD(T)/cc-pVTZ level of theory. Mayer bond order for all intrinsic reaction coordinate points was also calculated. Finally, it is theoretically proved that ABC dry powder extinguishes the fire mainly by chemical inhibition on H and OH radicals. [ABSTRACT FROM AUTHOR]