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Conversion of biomass-derived glucose to 5-hydroxymethylfurfural (HMF) is an important step for valorizing lignocellulosic biomass. In conventional reaction systems such as aqueous or water-organic solvent biphasic system, degradation of the formed HMF and other intermediates into undesired products is inevitable due to the presence of Bronsted acid, limiting HMF production efficiency. Here, we develop a novel reaction system consisting of heterogeneous catalyst with reduced Bronsted acidity and ionic liquid 1-ethyl-3-methylimidazolium bromide (EMIMBr) to achieve the efficient conversion of high-concentration glucose to HMF. A series of Al-containing materials was synthesized and characterized by N2 adsorption-desorption, XRD, XPS, FIIR, Py-IR and CO2 TPD, among which the Al2O3-b-0.05 prepared by simple alkaline treatment exhibited high Lewis acidity and low Bronsted acidity. The Al2O3-b-0.05 in the medium of EMIMBr leaded to the highest HMF yield of 49.7% from high-concentration glucose (up to 10 wt%), as is more efficient than the heterogeneous EMIMCl/Al2O3-b-0.05 and homogeneous EMIMBr/AlCl3 system. This work provides a paradigm of improving HMF production efficiency via the combined use of heterogeneous Lewis acid catalyst and ionic liquid.

Photocatalysis has exhibited huge potential in many reactions, but the design of metal-free photocatalytic material for selective upgrading of biomass is rarely achieved. Here, we report that the metal-free photocatalyst consisted of nitrogen-deficient carbon nitride (BNCN) and chlorin e6 (Ce6) can efficiently and selectively oxidize glucose into gluconic acid and glucaric acid. Introducing nitrogen defects could significantly enhance the optical absorption and modulate the band structure. In addition, the combination of Ce6 with BNCN further improve the optical absorption property and promote effective separation of photon-generated carriers. As expected, the resultant Ce6@BNCN catalyst gave a total selectivity of gluconic acid, glucaric acid and arabinose as high as 70.9% at glucose conversion up to 62.3%, as is superior to previously reported photocatalytic systems. The mechanism for the enhancement of catalytic performance and the reaction pathway were revealed by experimental studies combined with DFT calculations.

To achieve efficient degradation of pharmaceutical and personal care products (PPCPs), dual reaction centers ZnO@FePc photo-Fenton catalysts with high-speed electron transmission channel were designed through surface hydroxyl-induced assembly. In ZnO@FePc catalytic system, the photocatalysis center of ZnO and Fenton catalytic center of FePc were formed simultaneously. Concept and process for the control of hydroxyl groups to construct a dual reaction center ZnO@FePc photo-Fenton catalyst were verified ingeniously based on the density functional theory (DFT) analysis and experimental results. A series of catalysts, including ZIF-8 (400 ℃-N2), FePc (400 ℃-N2), ZIF-8 (400 ℃)-FePc (400 ℃) and ZnO@FePc were prepared and characterized by XRD, FTIR, TEM, BET, XPS, PL and DRS, respectively. The ZnO@FePc catalyst showed superior performance for the photo-Fenton degradation of ibuprofen, affording degradation rate larger than 90 % within just 10 min under simulateed sunlight. The excellent performance of ZnO@FePc catalyst is mainly attributed to the synergistic effect between dual reaction centers of ZnO@FePc. This work provides a novel method to construct dual reaction centers ZnO@FePc catalyst with efficient photo-generated electrons transmission link and to strengthen the synergistic effect of dual reaction centers.

First-principles calculations have been carried out to investigate the adsorption of a hydrogen adatom on 24 metal doped α-Zr (0 0 0 1) surfaces in both a vacuum and an implicit solvation environment. The dopant are the elements in the 4th and 5th periods in the periodic table. Doping elements at the tail of the 4th and 5th periods can significantly reduce the hydrogen pickup in a vacuum environment. A weighted d-band center theory is used to analyze the doping effect. On the other hand, the hydrogen adsorption energies in water are relatively lower for all doped slabs and the surface adsorption of hydrogen adatom is stronger than that in a vacuum environment, especially, for the slabs with doping elements at the tail of the 4th and 5th periods. In the solvation environment, electronegativity difference affects the adsorption. Doping elements Ag, Ga, Ge, Sn, and Sb can reduce the hydrogen pickup in vacuum, while Ag and Cu can reduce the hydrogen pickup of the zirconium alloys in solvent environment.

In this work, we perform a comprehensive study of five phenomena of LiNi1-2xCoxMnxO2 (NCM) (x = 0–1/3) cathodes at the end of charge (phase reaction, crack propagation, Li-Ni exchange, phase transition, and oxygen evolution), using first-principle calculations within the DFT + U framework. Based on our results, we have located the obstacles toward unity efficiency and revealed that the degradation strongly depends on the Ni concentration and the depth of charge. The threshold capacities for degradation of LiyNi1-2xCoxMnxO2 are 130–140 mA·hg−1 (y

Production of 5-hydroxymethylfurfural (HMF) is a pivotal step in biorefinery. However, the intrinsic HMF production efficiency in traditional catalytic systems are low owing to the side-reactions. Here we report the highly efficient transformation of carbohydrates to HMF via tandem catalysis in heterogeneous catalytic system. The combination of Al and Sn co-modified hydroxyapatite catalyst (Al/Sn-HAP) with ionic liquid exhibit a low activation energy of 68.4 kJ mol-1, affording HMF yields of 70.5 and 46.6% at glucose loading of 10 and 40 wt%, respectively. Compared with other catalysts, Al/Sn-HAP exhibits remarkably higher Lewis acid concentration, specific surface area and pore dimeter with slight Bronsted acid, as are beneficial for glucose isomerization. The efficient conversion of maltose, cellobiose and starch to HMF are achieved via the triple tandem pathway consisted of hydrolysis, isomerization and dehydration with inhibited side-reaction. Besides, the Al/Sn-HAP catalyst after regeneration can be reused without decrease of catalytic performance.

To achieve efficient degradation of dye in wastewater, the core-shell nickel cobalt spinel coated with iron phthalocyanine (NiCo2O4@FePc) catalyst was prepared via a facile template method and investigated as heterogenous catalyst for degradation of dye in Fenton process. The catalysts were systematically characterized by transmission electron microscopy (TEM), N2 adsorption/desorption isotherms, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. The results indicated that the NiCo2O4@FePc catalyst exhibits core-shell structure with abundant oxygen vacancies and high specific surface area (261.9 m2/g). NiCo2O4@FePc showed much higher catalytic activity for the mineralization of (TOC removal rate > 90%) RhB than nickel cobalt spinel (NiCo2O4), iron phthalocyanine (FePc) and the physical mixture of NiCo2O4 and FePc (NiCo2O4-FePc-M). The radical scavenging experiments and reaction kinetics experiments revealed that the excellent catalytic perormance of NiCo2O4@FePc benefits from the efficient production of •O2− and •OH radical. Moreover, the catalytic performance of NiCo2O4@FePc can be well maintained in the presence of inorganic anions (HCO3− and Cl−), natural organic matter or tap water. Besides, the liquid stability and resubility of NiCo2O4@FePc were demonstrated by filtration and recyling experiment. This work can provide new insight for construction of Fe-based heterogenous catalysts which are promising for the efficient elimination of organic pollutants.

The mineralization of organic pollutants under visible light is challenging, limiting the practical application of photocatalytic technology in wastewater treatment. To achieve the efficient mineralization of Acid red 3R (AR3R), a series of honeycombed catalysts (TiO2, C-TiO2-X, Au@TiO2 and Au@C-TiO2-X) were prepared via a facile in situ synthetic method and characterized by XRD, TEM, BET, XPS and DRS, respectively. The introduction of C and Au species promote the simultaneous generation of •O2− and •OH over Au@C-TiO2-X under visible light radiation. The Au@C-TiO2-X catalyst showed superior performance for the deep mineralization of AR3R, affording a TOC removal rate larger than 90 % within 240 min under visible light (> 420 nm). The photocatalytic degradation mechanism of AR3R is proposed according to UV–vis and in situ DRIFTS analysis. The superior photocatalytic activity of Au@C-TiO2-X is attributed to the synergistic effect of •O2− and •OH owing to C doping and Au deposition.

Chemical and physical adsorption of a H 2 O molecule on a Zr (0 0 0 1) surface is studied by first principle calculations. A surface zirconium atom is substituted by a metal element atom in the 4th and 5th period of the periodic table to investigate the doping effect on the water adsorption. Doping elements Ge, Sn, Sb, Zn, Ga, Ru, Rh, Pd, Ag, Cr, Mn, Fe, Co, Ni, Cu, Nb, and Mo can increase the oxidation resistance. This strategy can be used to design high oxidation resistance cladding material for light water reactor.