Supramolecular network-mediated spatial confinement-electronic bridge framework to construct biomass carbon-coated AlZr dual-acidic solid acid catalyst for efficient conversion of cellulose.

Catalytic pyrolysis of diesel derived from paraffinic and intermediate based crude oil over solid base and acid catalysts

Tantalates-based solid acid modified Bi°-BiVO4 for synergistic reduction of aromatic nitrobenzene with a significant enhancement effect

Ruscogenin production from Ophiopogon japonicus extract by novel pressurized hydrolysis with solid acid Amberlyst-15

Fixing silicotungstic acid onto activated bentonite assisted by ultrasonic waves and its application as a solid acid catalyst for levulinic acid esterification into butyl levulinate

Production of 5-hydroxymethylfurfural from cellulose in a fully component-recoverable catalytic system containing modified montmorillonite solid acid

Sulfonated plantain-peel solid acid for FFA esterification pretreatment of waste cooking oil: synthesis, characterization, and RSM optimization

Construction of TiO2-WO3 solid acid catalysts and performance study on catalytic degradation of chlorobenzene and methylbenzene mixture

Enhanced hydrolysis of cellulose by magnetic carbon-based solid acid catalysts: Effect of hydrothermal pretreatment on the precursor.

Honeycomb-like 3D porous carbon confined polymeric solid acid for boosting biodiesel production from Jatropha curcas oil

One-step fabrication of NiSO4/NiO solid acid catalyst for rapid CO2 desorption in CO2-loaded amine solutions

The carbonate reservoir of the Shunbei oilfield is characterized by deep burial depth and high temperature. During acid fracturing, the reaction rate between conventional acid systems and the rock is relatively fast, leading to a limited effective acid penetration distance. To extend the acid penetration distance, a combination of solid retarded acid and conventional acid was used in field operations. The effectiveness of the solid retarded acid depends on its acid generation pattern, making it necessary to study the acid generation behavior of the solid retarded acid. This paper establishes a frame for evaluating the solid retarded acid, including tests for solid retarded acid solubility, acid concentration, and acid-etched fracture conductivity. Based on the test results, the acid generation pattern of solid retarded acid was analyzed, its slow-generation performance was evaluated, and an acid generation model was established. Finally, by integrating the acid generation model with the existing acid fracturing model, the effective distance of solid retarded acid was predicted. The study shows that the solubility of acid-generating materials is influenced by both temperature and solid retarded acid concentration. When the concentration of solid retarded acid exceeds 25%, it does not completely dissolve at room temperature, but can fully dissolve after 40 min at 120 °C. The acid concentration is significantly affected by temperature, with an acid concentration of about 1.6 mol/L at room temperature and up to 3.1 mol/L at high temperatures, comparable to a 12% hydrochloric acid concentration. Solid retarded acid exhibits good slow-generation performance, with a comprehensive reaction rate approximately one-third of that of cross-linked acid. When the acid-rock contact time is around 3 h, the acid-etched fracture conductivity of solid retarded acid can remain above 5 D·cm under a closure pressure of 60 MPa. The predicted effective acid penetration distance of solid retarded acid can reach over 150 m, under typical conditions of Shunbei oilfield. The findings of this study can serve as a reference for the design and optimization of solid retarded acid fracturing.

The persistent accumulation of polyolefin plastic waste poses a significant environmental challenge, while its sustainable conversion into valuable olefins is limited by poor accessibility and severe coking of conventional microporous zeolite catalysts. Here, we report a rationally designed amorphous-crystalline composite (ACC) catalyst that integrates short-range ordered SOD-type domains into an amorphous aluminosilicate matrix to decouple acidity from micropore confinement. This hybrid architecture provides both open diffusion channels and accessible acid sites, enabling efficient C-C bond scission while suppressing secondary reactions. In low-density polyethylene cracking at 440 °C and a catalyst-to-feed weight ratio of 10/1, the optimized ACC catalyst achieved an exceptional C3-C5 olefin selectivity of 94.92% and a yield of 88.08 wt %, outperforming commercial ZSM-5 and USY by factors of more than 13 and 37, respectively. The catalyst exhibited outstanding stability over 20 consecutive cycles with minimal coke formation (1.13 wt %) and broad applicability across various polyolefins and postconsumer plastic wastes. This work establishes a generalizable design strategy for decoupling acidity and mass transport in solid acid catalysts, offering a robust platform for the sustainable valorization of polyolefin waste.

The fragment-based approach is a promising strategy for applying correlated-wavefunction methods to lattice energies of molecular solids. A key requirement is the efficient inclusion of the long-distance and nonadditive contributions to the many-body expansion (MBE) of the lattice energy. This is especially important in crystals of polar molecules, where MBE converges slowly with distance. In this context, we compare the simplest coupled-cluster approach-the random-phase approximation (RPA)-against the well-established methodology of Møller-Plesset (MP) perturbation theory. Using the examples of solid ammonia, methanol, and formic acid, we show that the RPA with singles corrections based on the Kohn-Sham (KS) Perdew-Burke-Ernzerhof (PBE) orbitals yields near-benchmark accuracy for the two-body contributions. However, for any PBE-based variant of RPA, the three- and four-body contributions suffer from artifacts. For the nonadditive terms, the Hartree-Fock (HF) orbitals appear necessary. In fact, we find that the HF-based RPA with additional corrections recovers the nonadditive interactions about as accurately as the more expensive MP2.5 method. This is a departure from the typical KS-based RPA and an indication that the HF-based RPA can serve as an alternative to the usual MP methods in accurate approximations of the crystal lattice energy.

The efficient generation of structurally diverse rare ginsenosides from abundant precursors remains a significant challenge. In this study, a heterogeneous catalyst, 12-tungstosilicic acid supported on mesoporous silica (HSiW@mSiO2), was developed for the transformation of ginsenoside Re in aqueous ethanol solution. The reaction was conducted under mild conditions, and the products were systematically analyzed using high-performance liquid chromatography coupled with multistage tandem mass spectrometry and high-resolution mass spectrometry. A total of 24 transformation products were identified, arising from deglycosylation, epimerization, dehydration, cyclization, and nucleophilic addition reactions. Structural elucidation revealed the formation of deglycosylated, hydrated and dehydrated derivatives, C-20 epimers, and novel ethoxylated protopanaxatriol-type ginsenosides resulting from solvent incorporation at the C-24(25) or C-20 position. Product distribution varied with reaction parameters, including solvent composition, reaction time, temperature, and catalyst dosage. The synthesized HSiW@mSiO2 catalyst could be readily recovered by centrifugation and reused for five consecutive cycles, with complete conversion of ginsenoside Re maintained in the first two runs and a gradual decline in conversion to approximately 50% by the fifth cycle. This work demonstrates the efficacy of solid acid catalysts in enabling the structural diversification of ginsenosides through solvent-involved pathways.

Among imines, nitrogen-unprotected ketimines (N–H ketimines) are valuable precursors to nitrogen-containing compounds. However, their applications are limited compared with those of nitrogen-protected ketimines (N–R ketimines) owing to difficulties in synthesis and purification. We develop remarkably simple methods for synthesizing and isolating high-purity N–H ketimines and N–H ketimine hydrochlorides via the dehydration–condensation of ketones with stoichiometric ammonia, generated in situ with inorganic solid acid catalysts. Our methods offer exceptionally broad substrate scope, use non-toxic and reusable catalysts, do not require tedious synthetic steps, are inexpensive, and are suited to large-scale production. Additionally, ketones can be easily converted to N–R ketimines, α-aminonitriles, and hydantoins in one pot via N–H ketimines. All products can be isolated by filtration or concentration; other purification methods, such as column chromatography, are not required. This study guides the advancement of the design of new transition metal catalysts and pharmaceutical synthesis.

Hydrothermal Reactions of Biomass-Derived Platform Molecules: Catalytic Decomposition Mechanisms of Glucose and Fructose over a Solid Acid Catalyst

Phthalic Acid-Terminated Hyperbranched Poly(ether ketone) as a Solid Acid Catalyst for Cellulose Hydrolysis

Cyclopentadiene is an important intermediate that is widely used in the production of useful chemicals, high-density aviation fuels and polymers. Conventional technologies for the production of cyclopentadiene from fossil energies suffer from low yield and selectivity. Therefore, the selective production of cyclopentadiene from renewable biomass is highly expected. In this work, a series of metal phosphates were found to be effective solid acid catalysts for the selective synthesis of cyclopentadiene from the dehydration of 1,3-cyclopentanediol, a platform compound that can be obtained from the aqueous phase rearrangement of furfuryl alcohol followed by hydrogenation. Among the investigated catalysts, lanthanum phosphate (LaP) exhibited the best performance. Over it, 100% 1,3-cyclopentanediol conversion and higher than 90% carbon yield of cyclopentadiene were achieved at 473 K under atmospheric pressure. Based on the results of characterization, the excellent performance of LaP catalyst can be rationalized by its higher amount of acid sites and average pore size.

The research was carried out in two distinct plastic greenhouses. The first location was at the University of Anbar, College of Agriculture first research station. The second location was in Heet city, Aldolab village during the growing season of 2022-2023, with the goal of investigating the effect of spraying with seaweed extract(2 and 4 ml L-1), amino acid "arginine" (100 and 200 mg L-1), and growth regulator brassinolide (0.05 and 0.10 mg L-1)on the quality of fruits of Albion strawberry plants under protected environment conditions. in addition to the control treatment of spraying with distilled water only for the three factors. A factorial experiment with three factors was conducted according to the randomized complete block design (RCBD). Spraying with seaweed extract, arginine and brassinolide had a significant effect on all the traits of the quality of the studied fruits, the concentrations of seaweed extract (4 ml L-1), arginine (200 mg L-1), and brassinolide (0.01 mg L-1) contributed to the best results for the traits (percentage of total sugars, the ratio between sugars and acidity, total soluble solid, anthocyanin and ascorbic acid). The values were (7.34 and 6.59%, 6.83 and 6.64%, 7.11 and 6.35%), (20.61 and 14.60, 17.99 and 14.17, 18.66 and 13.39), (9.25 and 8.34%, 8.87 and 8.24%, 9.10 and 8.34%), (59.57 and 48.91 mg 100 g-1, 53.81 and 43.02 mg 100 g-1, 52.34 and 42.98 mg 100 g-1), (50.95 and 57.73 mg 100 g-1, 50.18 and 56.37 mg 100 g-1, 50.39 and 55.96 mg 100 g-1), for the two sites respectively. On the other hand, the above treatments led to lowering the ratios of total acidity in fruits at both sites were (0.38 and 0.48%, 0.40 and 0.49%, 0.40 and 0.51%), respectively.The interaction between the two and three factors had a significant effect on most of the studied traits depending on the type of trait studied.