利用二萘酚副产亚钠生产焦亚硫酸钠的研究

二萘酚副产亚硫酸钠主含量低,杂质成分复杂,产品附加值低,只能用在低端行业。根据二萘酚副产亚硫酸钠中杂质的性质,利用二萘酚在酸性、常温条件下不溶于水的特性,向副产亚硫酸钠溶液中通入二氧化硫进行酸化,过滤回收副产亚钠中的二萘酚,向回收二萘酚后的滤液中加入生石灰,再次向溶液中通入二氧化硫,使生石灰转化为易溶于水的亚硫酸氢钙,亚硫酸氢钙与溶液中的硫酸钠反应生成不溶于水的硫酸钙沉淀,通过过滤的方式除去,除去二萘酚和硫酸钠的亚硫酸氢钠溶液经过高真空低温蒸发、离心过滤干燥,得到质量分数96.5%以上的优等品焦亚硫酸钠,具有明显的经济效益。

乙醛酸合成的研究

乙醛酸，别名甲醛甲酸，是最简单的酮酸，有醛和酸的性质，通常分布于未成熟的水果及某些动物组织的体液中，广泛用于合成清漆原料、香料、医药、染料、塑料、工业化学品的中间体，也可用于生产口服青霉素、香兰素、乙基香兰素和尿囊素等产品。目前合成乙醛酸的方法有：乙烯氧化法、乙醇酸转化法、乙二醛氧化法、二氧化酸化、

Ultra-deep oxidative desulfurization of fuel with H_2O_2 catalyzed by phosphomolybdic acid supported on silica

A highly active catalyst of phosphomolybdic acid ~HPMo） was prepared and applied in the catalytic oxidative desulfurization （CODS） system. The catalyst was characterized by FT-IR, XRD, XPS and superconducting NMR. The influences of rn（catalyst）/m（oil）, V（H202）fV（oil）, reaction temperature and reaction time on the fractional conversion of benzothiophene （BT） and dibenzothiophene （DBT） were investigated. GC-MS and micra-coulometric methods were employed to investigate the reaction. The catalyst has high desulfurization activity in the removal of BT and DBT under mild conditions. The recycling experiments indicated that DBT and BT removal could still reach 95.2% and 95.7% after 10 cycles.

Recent advances in metal-free catalysts for the synthesis of cyclic carbonates from CO_2 and epoxides

The aim of ＂green chemistry＂ and ＂atom economy＂ is to utilize carbon dioxide and replace harmful reactants such as CO and phosgene for the production of cyclic carbonates. In this paper, metal-free catalysts including organic bases, ionic liquids, supported catalysts, organic copolymers and carbon materials for the synthesis of cyclic carbonates by the cycloaddition of carbon dioxide to epoxides are reviewed. Recent advances in the design of the catalysts and the understanding of the reaction mechanism are summarized and discussed. The synergistic effects of organic bases and hydrogen bond donors, organic bases and nucleophilic anions, hydrogen bond donors and nucleophilic anions and active components and supports are highlighted. The challenge is to develop metal-free catalysts suitable for carbon dioxide capture and fixation. The ultimate goal is to synthesize cyclic carbonates in a flow reactor directly using carbon dioxide from industrial flue gas at ambient temperature and atmospheric pressure. By using synergetic effects, a multi-functional approach can meet the design strategy of metal-free catalysts for carbon dioxide adsorption and activation as well as epoxide ring opening.

Effect of NH_4^+ exchange on CuY catalyst for oxidative carbonylation of methanol

NaY and ion exchanged NaNH4Y zeolite with NH4NO3 were used as the support to prepare CuY cata‐lysts by a high temperature anhydrous interaction between the support and copper （II） acety‐lacetonate Cu（acac）2. The catalysts were used for the oxidative carbonylation of methanol to dime‐thyl carbonate （DMC） at atmospheric pressure. The textural and acidic properties of NaNH4Y zeolite and the CuY catalysts were investigated by X‐ray diffraction, scanning electron microscopy, N2 ad‐sorption‐desorption, temperature programmed reduction of H2, X‐ray photoelectron spectroscopy and temperature programmed desorption of NH3. With increasing NH4NO3 concentration, the NH4＋exchange degree increased while the crystallinity of the zeolite remained intact. Crystalline CuO was formed when the NH4＋exchange degree of NaNH4Y was low, and the corresponding CuY catalyst showed low catalytic activity. With increasing of the NH4＋exchange degree of NaNH4Y, the content of surface bound Cu＋active centers increased and the catalytic activity of the corresponding CuY catalyst also increased. The surface bound Cu＋content reached its maximum when the NH4＋ex‐change degree of NaNH4Y reached towards saturation. The CuY exhibited optimal catalytic activity with 267.3 mg/（g·h） space time yield of DMC, 6.9%conversion of methanol, 68.5%selectivity of DMC.

The Future Programming of Acid Rain and SO_2 Control in China

This paper describes a programme for controlling acld rain and SO2 pollutions in the coming years in China. It embraces the control targets in some respects, such as precipitation acidity, urban SO2 pollution, SO2 emission sources and its total emission, and various control measures, such as limiting the exploitation of high sulfur coal, promoting steam coal washing, strengthening SO2 emission sources control and readjusting their special layout, enhancing total SO2 emission control, implementing the licence system of pollution discharge and the exchange system of SO2 emission and revising the SO2 emission standards.

Promotional effect of H_3PO_4 on ceria catalyst for selective catalytic reduction of NO by NH_3

A series of H3PO4-modified CeO2 samples were prepared by impregnation of CeO2 with H3PO4solution,and evaluated for the selective catalytic reduction of NOx by NH3.The samples were characterized by X-ray diffraction,N2 adsorption-desorption,infrared spectroscopy,Raman spectroscopy,X-ray photoelectron spectroscopy,temperature-programmed desorption of NH3,and temperature-programmed reduction of H2.The results showed that more than 80%NO conversion was achieved in the temperature range 250-550℃ over the H3PO4-CeO2 catalyst.The enhanced catalytic performance could be ascribed to the increase in acidic strength,especially Bronsted acidity,and reduction in redox properties of the CeO2 after H3PO4 modification.

Electrochemical CO_2 reduction to formic acid on crystalline SnO_2 nanosphere catalyst with high selectivity and stability

A novel catalyst for CO2 electroreduction based on nanostructured SnO2 was synthesized using a facile hydrothermal self-assembly method. The electrochemical activity showed that the catalyst gave outstanding catalytic activity and selectivity in CO2 electroreduction. The catalytic activity and formate selectivity depended strongly on the electrolyte conditions. A high faradaic efficiency, i.e., 56%, was achieved for formate formation in KHCO3 （0.5 mol/L）. This is attributed to control of formate production by mass and charge transfer processes. Electrolysis experiments using SnO2-50/GDE （an SnOz-based gas-diffusion electrode, where 50 indicates the 50% ethanol content of the electrolyte） as the catalyst, showed that the electrolyte pH also affected CO2 reduction. The optimum electrolyte pH for obtaining a high faradaic efficiency for formate production was 8.3. This is mainly because a neutral or mildly alkaline environment maintains the oxide stability. The fara- daic efficiency for formate production declined with time. X-ray photoelectron spectroscopy showed that this is the result of deposition of trace amounts of fluoride ions on the SnO2-50/GDE surface, which hinders reduction of CO2 to formate.

Novel visible-light-responding InVO_4-Cu_2O-TiO_2 ternary nanoheterostructure: Preparation and photocatalytic characteristics

A novel visible-light-responding InVO4-Cu2O-TiO2 ternary nanoheterostructure was designed on the basis of the strategy of energy gap engineering and prepared through ordinary wet chemistry methods. The as-prepared nanoheterostructure was characterized by X-ray powder diffraction（XRD）, transmission electron microscopy（TEM）, high-resolution transmission electron microscopy（HRTEM） and diffuse reflectance ultraviolet-visible spectroscopy（UV-vis/DRS）. The TEM and HRTEM images of 10%InVO4-40%Cu2O-50%TiO2 confirm the formation of nanoheterostructures resulting from contact of the nanosized TiO2, Cu2O and InVO4 in the size of 5–20 nm in diameter. The InVO4-Cu2O-TiO2 nanoheterostructure, when compared with TiO2, Cu2O, InVO4, InVO4-TiO2 and Cu2O-TiO2, shows significant enhancement in the photocatalytic performance for the degradation of methyl orange（MO） under visible-light irradiation. With a 9 W energy-saving fluorescent lamp as the visible-light source, the MO degradation rate of 10%InVO4-40%Cu2O-50%TiO2 reaches close to 90% during 5 h, and the photocatalytic efficiency is maintained at over 90% after six cycles. This may be mainly ascribed to the matched bandgap configurations of TiO2, Cu2O and InVO4, and the formations of two p-n junctions by the p-type semiconductor Cu2O with the n-type semiconductors TiO2 and InVO4, all of which favor spatial photogenerated charge carrier separation. The X-ray photoelectron spectroscopy（XPS） characterization for the used 10%InVO4-40%Cu2O-50%TiO2 reveals that only a small shakeup satellite peak appears for Cu（II） species, implying bearable photocorrosion of Cu2O. This work could provide new insight into the design and preparation of novel visible-light-responding semiconductor composites.

Nitrous Oxide and Methane Emissions as Affected by Water,Soil and Nitrogen

Specific management of water regimes, soil and N in China might play an important role in regulating N2O and CH4 emissions in rice fields. Nitrous oxide and methane emissions from alternate non-flooded/flooded paddies were monitored simultaneously during a 516-day incubation with lysimeter experiments. Two N sources (15N-(NH4)2SO4 and 15N-labeled milk vetch) were applied to two contrasting paddies: one derived from Xiashu loess (Loess) and one from Quaternary red clay (Clay). Both N2O and CH4 emissions were significantly higher in soil Clay than in soil Loess during the flooded period. For both soil, N2O emissions peaked at the transition periods shortly after the beginning of the flooded and non-flooded seasons. Soil type affected N2O emission patterns. In soil Clay, the emission peak during the transition period from non-flooded to flooded conditions was much higher than the peak during the transition period from flooded to non-flooded conditions. In soil Loess, the emission peak during the transition period from flooded to non-flooded conditions was obviously higher than the peak during the transition period from non-flooded to flooded conditions except for milk vetch treatment. Soil type also had a significant effect on CH4 emissions during the flooded season, over which the weighted average flux was 111 mg C m-2 h-1 and 2.2 mg C m-2 h-1 from Clay and Loess, respectively. Results indicated that it was the transition in the water regime that dominated N2O emissions while it was the soil type that dominated CH4 emissions during the flooded season. Anaerobic oxidation of methane possibly existed in soil Loess during the flooded season.

Conversion of glycerol to acrolein by mesoporous sulfated zirconia-silica catalyst

A mesoporous sulfated zirconia-silica catalyst bearing only Br？nsted acid sites converted glycerol to acrolein in 81%yield with 82% selectivity.Space time yield as high as 9.0 mmol h^（-1） g_（cat）^（-1） was achieved even at a low reaction temperature of 523 K.The catalytic activity and selectivity were higher than those of typical sulfated zirconia.It is proposed that the milder acidity due to dilution of zirconium species by silica and large pore size for faster diffusion contributed towards the better catalytic performance.

Preparation of chemical manganese dioxide from manganese sulfate

Chemical Manganese Dioxide （CMD） was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, easy operations, no pollutants, easily obtained raw materials and moderate reaction conditions. The synthesized manganese dioxide was characterized by XRD and SEM. The particles were small, consisting primarily of α-MnO2 and γ-MnO2. Experimental results showed that the optimum conditions were： MnSOa.H20 to NaOH ratio, 1.0：2.4; catalyst concentration （catalyst TF-2）, 6% of the MnSO4; initial solution pH, 11; reaction time and temperature, 20 min and 80 ℃; air flow, 0.20 m3/h; and, agitation rate, 700 r/rain. The conversion of MnSO4 can exceed 80% under these optimum conditions.

Effective photocatalytic conversion of formic acid using iron,copper and sulphate doped TiO_(2)

In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.

Electrochemically exfoliated graphene as high-performance catalyst support to promote electrocatalytic oxidation of methanol on Pt catalysts

Electrochemically exfoliated graphene(EEG)is a kind of high-quality graphene with few oxygen-containing functional groups and defects on the surface,and thereby is more suitable as catalyst support than other carbon materials such as extensively used reduced graphene oxide(rGO).However,it is difficult to grow functional materials on EEG due to its inert surface.In this work,ultra-small Pt nanocrystals(~2.6 nm)are successfully formed on EEG and show better electrocatalytic activity towards methanol oxidation than Pt catalysts on r GO.The outstanding catalytic properties of Pt catalysts on EEG can be attributed to the fast electron transfer through EEG and high quality of Pt catalysts such as small grain size,high dispersibility and low oxidation ratio.In addition,SnO2 nanocrystals are controllably generated around Pt catalysts on EEG to raise the poison tolerance of Pt catalysts through using glycine as a linker.Owing to its outstanding properties such as high electrical conductivity and mechanical strength,EEG is expected to be widely used as a novel support for catalysts.

Pickering interfacial biocatalysis with enhanced diffusion processes for CO_(2) mineralization

Utilization of carbon dioxide(CO_(2))has become a crucial and anticipated solution to address environmental and ecological issues.Enzymes such as carbonic anhydrase(CA)can efficiently convert CO_(2) into various platform chemicals under ambient conditions,which offers a promising way for CO_(2) utilization.Herein,we constructed a Pickering interfacial biocatalytic system(PIBS)stabilized by CA‐embedded MOFs(ZIF‐8 and ZIF‐L)for CO_(2) mineralization.Through structure engineering of MOFs and incorporation of Pickering emulsion,the internal and external diffusion processes of CO_(2) during the enzymatic mineralization were greatly intensified.When CO_(2) was ventilated at a flow rate of 50 mL min^(–1) for 1 h,the pH value of PIBS dropped from~8.00 to~6.50,while the average pH value of free system only dropped to~7.15,indicating that the initial reaction rate of CO_(2) mineralization of PIBS is nearly twice that of the free system.After the 8^(th) cycle reaction,PIBS can still produce more than 9.8 mg of CaCO_(3) in 5 min,realizing efficient and continuous mineralization of CO_(2).

Preparation and Photocatalytic Properties of Magnetically Separable TiO_2 Supported on Nickel Ferrite

A magnetically separable photocatalyst TiO2/SiO2/NiFe2O4 （TSN） with a typical ferromagnetic hysteresis was prepared by a liquid catalytic phase transfer method. When the intensity of applied magnetic field weakened to zero, the remnant magnetism of the prepared photocatalyst faded to zero. The photocatalytst can be separated from water when an external magnetic field is added and redispersed into aqueous solution after the external magnetic field is eliminated, that makes the photocatalysts promising for wastewater treatment. Transmission electron microscope （TEM） and X-ray diffractometer （XRD） were used to characterize the structure of the photocatalyst indicating that the magnetic SiOffNiFe204 （SN） particle was compactly enveloped by P-25 titania and Tit2 shell was formed. The magnetic composite showed high photocatalytic activity for the degradation of methyl orange in water. A thin SiO2 layer between NiFe2O4 and TiO2 shell prevented effectively the leakage of charges from TiO2 particles to NiFe2O4, which gave rise to the increase in photocatalytic activity. Moreover, the experiment on recycled use of TSN demonstrated a good repeatability of the photocatalytic activity.

Progress of electrochemical CO_(2)reduction reactions over polyoxometalate-based materials

Electrochemical CO_(2)reduction to value-added fuels and chemicals is recognized as a promising strategy to alleviate energy shortages and global warming owing to its high efficiency and economic feasibility.Recently,understanding the activity origin,selectivity regulation,and reaction mechanisms of CO_(2)reduction reactions(CO_(2)RRs)has become the focus of efficient electrocatalyst design.Polyoxometalates(POMs),a unique class of nanosized metal-oxo clusters,are promising candidates for the development of efficient CO_(2)RR electrocatalysts and,owing to their well-defined structure,remarkable electron/proton storage and transfer ability,and capacities for adsorption and activation of CO_(2),are ideal models for investigating the activity origin and reaction mechanisms of CO_(2)RR electrocatalysts.In this review,we focus on the activity origin and mechanism of CO_(2)RRs and survey recent advances that were achieved by employing POMs in electrocatalytic CO_(2)RRs.We highlight the significant roles of POMs in the electrocatalytic CO_(2)RR process and the main factors influencing selectivity regulation and catalytic CO_(2)RR performance,including the electrolyte,electron-transfer process,and surface characteristics.Finally,we offer a perspective of the advantages and future challenges of POM-based materials in electrocatalytic CO_(2)reduction that could inform new advancements in this promising research field.

Novel hydrazine-bridged covalent triazine polymer for CO_2 capture and catalytic conversion

Carbon dioxide（CO_2） capture and catalytic conversion has become an attractive and challenging strategy for CO_2 utilization since it is an abundant, inexpensive, and renewable C1 resource and a main greenhouse gas. Herein, a novel hydrazine-bridged covalent triazine polymer（HB-CTP） was first designed and synthesized through simple polymerization of cyanuric chloride with 2,4,6-trihydrazinyl-1,3,5-triazine. The resultant HB-CTP exhibited good CO_2 capture capacity（8.2 wt%, 0 °C, and 0.1 MPa） as well as satisfactory recyclability after five consecutive adsorption-desorption cycles. Such a polymer was subsequently employed as a metal-free heterogeneous catalyst for the cyclo-addition of CO_2 with various epoxides under mild and solvent-free conditions,affording cyclic carbonates with good to excellent yields（67%–99%） and high functional-group tolerance. The incorporation of hydrazine linkages into HB-CTP＇s architecture was suggested to play the key role in activating epoxides through hydrogen bonding. Moreover, HB-CTP can be reused at least five times without significant loss of its catalytic activity.

Catalytic synthesis of diethyl carbonate with supported Pd-Cu bimetallic nanoparticle catalysts:Cu(Ⅰ) as the active species

Cupric oxide （CuO） and copper-cuprous oxide （Cu-Cu2O） nanoparticles were prepared by a simple hydrothermal method for the synthesis of diethyi carbonate （DEC） from ethanol. During these syntheses, varying NaOH and glucose concentrations were applied to explore and pinpoint the active species. It was found that PdCl2/CuO and PdCI2/Cu-Cu2O both catalysts exhibited good thermal stability and morphology. The results of catalytic tests showed that the catalysts prepared with 5 mol/L NaOH show superior catalytic performances because of their lower extent of agglomeration. It is noteworthy that the PdC12/Cu-Cu2O catalysts were the most active, especially the PdCl2/Cu-Cu2O catalyst prepared with 10 mmol glucose and having a higher Cu2O concentration. In Pd（ll）-Cu（II） （PdCl2/CuO） catalysts, there is an induction period, during which Pd（II） is reduced to Pd（0）, that must occur prior to electron transfer between Pd and Cu, and this can slow the catalytic reaction. To further pinpoint the active species, PdCl2/Cu-Cu2O catalysts with different Cu2O contents were prepared by controlling the dosages of glucose. The maximum DEC yield obtained with these catalysts was 151.9 mg.g-1.h-1, corresponding to an ethanol conversion of 7.2% and 97.9% DEC selectivity on an ethanol basis. Therefore, it was concluded that Cu＋ was the active species in this catalytic system, possibly because a higher proportion of Cu＋ reduces the Pd2＋ concentration and limits the CO oxidation side reaction, thus increasing DEC selectivity. In addition, Cu＋ promotes electron transfer between Pd and Cu without an induction period, which could also promote the catalytic activity.