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Calcium hydroxide was used as a swelling agent and grinding aid to grind together with cellulose raw materials to prepare microfibrillated cellulose (MFC). Carbon dioxide was introduced to obtain MFC coated with calcium carbonate (CMFC). The effect of calcium hydroxide dosage on the fibrillation process of cellulose materials and the characteristics of MFCs and CMFCs were studied. Results show that when the dosage of calcium hydroxide was 5 % (based on cellulose materials), calcium hydroxide could be completely dissolved in water and had a swelling effect on cellulose materials. When the dosage reached 10 %, undissolved calcium hydroxide particles could serve as grinding media to assist in the fibrillation of cellulose materials. When the dosage exceeded 50 %, the auxiliary grinding effect of calcium hydroxide was more obvious. After accelerated carbonation, the generated calcium carbonate nanoparticles were coated on the surface of MFC, which increased its viscosity and decreased water retention value. The presence of calcium carbonate also facilitated the concentration, redispersion, and drying of MFC. The pretreatment, mechanical fibrillation, and accelerated carbonation were carried out in the same equipment without the need for heating or washing. Therefore, this study provides a in situand one step method for the preparation of MFC.

Based on three datasets of the Chinese Social Survey (CSS) 2013, 2015, and 2017 and the National Statistical Yearbook, this study examined whether and in what ways using the Internet may or may not affect the public evaluation of government environmental governance (GEG). There are three main findings. First, Internet use has a negative influence on the public evaluation of GEG. Second, there has been an urban-rural difference in terms of Internet use; especially for the rural resident, increasing their use of the Internet significantly lowered their evaluation of GEG. Third, Internet use affects GEG mainly through political trust, whilst it tends to enhance people’s perception of environmental problems; however, it has little influence on their evaluation of GEG. This finding implies that public evaluation of GEG should be viewed as an important inter-subjective dimension of GEG; especially in the Internet era, it has become increasingly necessary for the government to not only continuously improve the quality of governance by dealing with actual/practical environmental issues, but also enhance its ability to react to the public opinions online effectively and appropriately.

In this work, a core–shell structured CeO2@Co3O4catalyst was successfully prepared by using a zeolitic imidazolate framework-based material as a sacrificial template. The structure, morphology, and physicochemical characteristics of these materials were investigated by X-ray diffraction, N2sorption, Fourier transform infrared spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, and temperature-programmed reduction studies. Compared with pure Co3O4and CeO2, the CeO2@Co3O4sample displayed superior catalytic performance (T90= 225 °C) toward toluene oxidation. Results demonstrated that the CeO2@Co3O4sample exhibited a core–shell structure, with hierarchically wrinkled surfaces. This unique structure, especially the interface between the core and the shell, endowed the CeO2@Co3O4catalyst with better activity. In addition, there was a synergistic effect between cerium and cobalt oxides in the core–shell bimetallic sample, which was responsible for the improved performance of the material. Moreover, surface-active oxygen species involved and played a significant role in toluene oxidation.

In this study, graphite powder (GP) was introduced into the conductive cellulose/polypyrrole (PPy) composite films to increase their conductivity and thermal stability. The GP was dispersed in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) before the dissolution of cellulose, and the cellulose/GP/PPy films were prepared by in situ chemical polymerization of PPy nanoparticles on the film surface. The structural characteristics and properties of the composite films were investigated in detail. The GP flakes, which were embedded in the cellulose matrix, increased the thickness and decreased the density of the films, leading to the decrement of mechanical properties. However, the thermal stability of the films was significantly improved by the incorporation of graphite, and the composite film could even substantially maintain the original shape after being burned. In addition, the electrical conductivity of the films was increased seven times, leading to the excellent electromagnetic interference shielding effectiveness. The cellulose/GP/PPy film could be considered as a potential candidate for the effective lightweight electromagnetic interference shielding materials in electronics, radar evasion, aerospace, and other applications.

A series of copper- and manganese-containing ordered mesoporous carbons (OMCs) were synthesized for the low-temperature selective catalytic reduction (SCR) of NO with NH3. The results demonstrated that NO conversion can be greatly improved by the addition of Cu or Mn. In addition, Cu and Mn had a synergetic effect and the optimal catalytic performance was obtained over the bimetallic catalyst Cu5Mn5-OMC. N2sorption, small-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to confirm the ordered mesoporous structures. Wide-angle XRD results showed that in the bimetallic catalysts some Cu ions were substituted by Mn ions, resulting in lattice contraction by the formation of a solid solution. X-ray photoelectron spectroscopy (XPS) results indicated that the O–CO groups and chemisorbed oxygen species increased with the addition of Cu or Mn. Temperature-programmed desorption of CO/CO2and NH3(CO/CO2-TPD and NH3-TPD) results verified that the acidity of the catalyst was enhanced by the addition of Cu and Mn and the bimetallic catalyst Cu5Mn5-OMC had the strongest acidity. Temperature-programmed reduction of H2(H2-TPR) results showed that Cu5Mn5-OMC had the strongest oxidizing capacity. Based on the above analysis, a possible synergetic catalytic effect was proposed through the electron transfer between Cu and Mn ions.

Abstract: The perovskite metal-oxides LaNi x Fe1−x O3 (0≤ x ≤1) were synthesized by a sol–gel method and investigated for the DR, POM, and CRM into synthesis gas. The catalysts were characterized by using XRD, BET, CA, SEM, EDS, HR-TEM, EDX and TPR in order to investigate the influence of the preparation parameters and evaluation condition. LaNi0.4Fe0.6O3 showed great stability, and fewer carbon deposits were detected on the spent catalyst after 1800min evaluation on TOS. The effect of GHSV on the catalytic performance was investigated. The results obtained showed the H2/CO molar-ratio was around 0.9, 1.7, and 1.1 over different catalysts for DR, POM and CRM, respectively. [Copyright &y& Elsevier]

To improve N2selectivity and lower the cost, WO3in V2O5/WO3–TiO2was substituted by a low cost composition Fe2O3for selective catalytic reduction (SCR) of NO with NH3. The SCR reaction over V2O5/Fe2O3–TiO2mainly followed the Eley–Rideal mechanism (i.e.the reaction between activated ammonia species and gaseous NO). There were two active components on V2O5/WO3–TiO2for the activation of adsorbed NH3(i.e.V5+and Fe3+). The acid sites on V2O5/Fe2O3–TiO2mainly resulted from the support Fe2O3–TiO2, so the adsorbed NH3preferred to be activated by Fe3+rather than by V5+. V5+on V2O5/Fe2O3–TiO2could accelerate the regeneration of Fe3+on Fe2O3–TiO2due to the rapid electron transfer between V5+and Fe2+on the surface, so the activation of adsorbed NH3by Fe3+was promoted. As some NH3adsorbed on V2O5/Fe2O3–TiO2was not activated by Fe3+, the inactivated NH3could then be activated by V5+on the surface. As a result, 2% V2O5/Fe2O3–TiO2showed excellent SCR activity, N2selectivity and H2O/SO2durability at 300–450 °C. Furthermore, the emission of 2% V2O5/Fe2O3–TiO2to the fly ash can be prevented by an external magnetic field due to its inherent magnetization. Therefore, 2% V2O5/Fe2O3–TiO2could be a promising low-cost catalyst in NO emission control.

A series of vanadium-doped CoCr2–xVxO4(x= 0–0.20) catalysts were prepared via the citric acid method and investigated for methane combustion. A significant improvement of the catalytic activity was observed over a CoCr1.95V0.05O4catalyst, and the catalytic activity reached 90% of methane conversion at 438 °C, which was 76 °C lower than that of the undoped catalyst. Vanadium doping caused disorder in the spinel structure and various changes in physicochemical properties. The higher concentration of suprafacial, weakly chemisorbed oxygen and the active cobalt species, especially Co3+, could play a major role in the oxidation reaction. Results of XRD, Raman, and XPS suggested that excess vanadium probably formed separate catalytically inactive VOxspecies, which would explain the decline of catalytic activity for samples with a higher substitution degree.