高效产H_2O_2气体扩散电极的研究

采用C/PTFE气体扩散电极在无隔膜体系中进行H2O2发生工艺研究,探讨了石墨和Vulcan XC-72碳黑两种碳材料以及电解电压、p H值对该反应过程的影响.结果表明,在较低的空气流量(1.41 cm3·min-1·cm-2)下,以Vulcan XC-72碳黑为表面的气体扩散电极相比石墨电极有较高的H2O2产率和电流效率,碱性条件比酸性条件下H2O2产率和电流效率更好;在2.6 V恒定电压下,2 h后,H2O2浓度达到了250 mg·L-1,电流效率从69.8%降到44.7%,单位产量能耗从5.87 k Wh·kg-1升高到9.16 k Wh·kg-1.     

ZnO-based heterostructures as photocatalysts for hydrogen generation and depollution: a review

Environmental Chemistry Letters - Energy shortage and escalating pollution are major challenges globally. Heterogeneous photocatalysis is one of the most cost-effective methods for producing...     

Bimetallic AgNi nanoparticles anchored onto MOF-derived nitrogen-doped carbon nanostrips for efficient hydrogen evolution

Hydrogen energy has long been recognized as a clean alternative to conventional fossil fuels, which can be applied in a wide range of transportation and power generation applications. The rational design and engineering of high-performance and robust catalysts for hydrogen evolution reaction(HER) shows not a great significance but a challenge for efficient electrochemical water splitting. Herein, a new type of Nibased Ni-ABDC precursor has been obtained, which leads to the formation of N-doped p...     

Advanced catalysts and effect of operating parameters in ethanol dry reforming for hydrogen generation. A review

Environmental Chemistry Letters - There is actually an intense research in ethanol dry reforming because bioethanol and carbon dioxide, a greenhouse gas, can be converted into syngas and,...     

New method for efficient control of hydrogen sulfide and methane in gravity sewers: Combination of NaOH and nitrite

• The combination of NaOH and nitrite was used to control harmful gas in sewers. • Hydrogen sulfide and methane in airspace were reduced by 96.01% and 91.49%. • Changes in sewage quality and greenhouse effect by chemical dosing were negligible. • The strong destructive effects on biofilm slowed down the recovery of harmful gases. • The cost of the method was only 3.92 × 10⁻³ $/m³. An innovative treatment method by the combination of NaOH and nitrite is proposed for controlling hydrogen sulfide and methane in gravity sewers and overcome the drawbacks of the conventional single chemical treatment. Four reactors simulating gravity sewers were set up to assess the effectiveness of the proposed method. Findings demonstrated hydrogen sulfide and methane reductions of about 96.01% and 91.49%, respectively, by the combined addition of NaOH and nitrite. The consumption of NaNO₂ decreased by 42.90%, and the consumption rate of NaOH also showed a downward trend. Compared with a single application of NaNO₂, the C/N ratio of wastewater was increased to about 0.61 mg COD/mg N. The greenhouse effect of intermediate N₂O and residual methane was about 48.80 gCO₂/m³, which is far lower than that of methane without control (260 gCO₂/m³). Biofilm was destroyed to prevent it from entering the sewage by the chemical additives, which reduced the biomass and inhibited the recovery of biofilm activity to prolong the control time. The sulfide production rate and sulfate reduction rate were reduced by 92.32% and 85.28%, respectively. Compared with conventional control methods, the cost of this new method was only 3.92 × 10⁻³ $/m³, which is potentially a cost-effective strategy for sulfide and methane control in gravity sewers.     

Production of hydrogen and value-added carbon materials by catalytic methane decomposition: a review

Environmental Chemistry Letters - Dihydrogen (H2), commonly named “hydrogen”, is attracting research interest due to potential applications in fuel cells, vehicles, pharmaceuticals and...     

Carbon materials toward efficient potassium storage: Rational design,performance evaluation and potassium storage mechanism

Potassium-ion batteries(PIBs) are potential “Beyond Li-ion Batteries” candidates for their resource advantage and low standard electrode potential. To date, the research on PIBs is in its early stages, the most urgent task is to develop high-performance electrode materials and reveal their potassium storage mechanism. For PIBs anode materials, carbon with tunable microstructure, excellent electrochemical activity, nontoxicity and low price is considered as one of the most promising anode materia...     

Process reconfiguration and intensification:An emerging opportunity enabling efficient carbon capture and low-cost blue hydrogen production

Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources,requiring additional CO₂ capture to decarbonize, which energy intense and costly. In a recent Green Energy & Environment paper, Cheng and Di et al. proposed a novel integration process referred to as SECLR_HC to generate high-purity H₂ by in-situ separation of H₂ and CO without using any additional separation unit. Th...     

Thermodynamic investigation of the effect of oxygen and hydrogen chloride potential upon generation and decomposition behavior of dioxins

The thermodynamic equilibrium of the C‐H‐O‐Cl system has been calculated to elucidate the generation and decomposition behavior of dioxins, and is discussed from the viewpoint of the oxygen and hydrogen chloride potential. The dioxins behavior is greatly dependent on the oxygen potential, i.e. higher temperature and oxygen potential lead to the complete decomposition of dioxins, while low hydrogen chloride potential under insufficient oxygen condition leads to an increase of multi‐chlorine displacement of dioxins.     

Performance of IUCN proxies for generation length

One of the criteria used by the International Union for Conservation of Nature (IUCN) to assess threat status is the rate of decline in abundance over 3 generations or 10 years, whichever is longer. The traditional method for calculating generation length (T) uses age‐specific survival and fecundity, but these data are rarely available. Consequently, proxies that require less information are often used, which introduces potential biases. The IUCN recommends 2 proxies based on adult mortality rate, = α + 1/d, and reproductive life span, = α + z^*RL, where α is age at first reproduction, d is adult mortality rate, RL is reproductive life span, and z is a coefficient derived from data for comparable species. We used published life tables for 78 animal and plant populations to evaluate precision and bias of these proxies by comparing and with true generation length. Mean error rates in estimating T were 31% for and 20% for , but error rates for were 16% when we subtracted 1 year ( ), as suggested by theory; also provided largely unbiased estimates regardless of the true generation length. Performance of depends on compilation of detailed data for comparable species, but our results suggest taxonomy is not a reliable indicator of comparability. All 3 proxies depend heavily on a reliable estimate of age at first reproduction, as we illustrated with 2 test species. The relatively large mean errors for all proxies emphasized the importance of collecting the detailed life‐history information necessary to calculate true generation length. Unfortunately, publication of such data is less common than it was decades ago. We identified generic patterns of age‐specific change in vital rates that can be used to predict expected patterns of bias from applying .     

A stochastic weather generation model for Alaska

A specific problem encountered in ecosystem-level simulation of Arctic ecosystems is the depth and extent of the driving variable record. Often, climate records are of short duration, gathered at locations different from the area to be simulated, or do not contain all the variables required by a given model. This paper addresses this problem for ecosystem simulation in Alaska with the development of a weather generator. The generator, called WGENAL, is based on the WGEN climate generator developed and validated in the 48 conterminous states. Because of the extreme variability of weather in Alaska that is not accommodated by the statistical metrics in the earlier model, a new climate generator was developed. WGENAL generates daily values of precipitation, maximum temperature, minimum temperature, solar radiation, and wind run. Precipitation is generated using a Markov chain-gamma model. A two-parameter gamma distribution is used to generate wind run. Temperatures and solar radiation are generated using procedures developed in the earlier study. Validation of the generator shows it provides adequate diurnal and seasonal weather records for Fairbanks. Other comparisons of synthetic weather with observed weather for sites north of the Brooks Range in Alaska are also within the error of the original data.     

Bio-based materials for high-end electronics applications

During the past decade, a shift of focus onto greener alternatives to petroleum-based plastics has spurred the development of bio-based resins for plastic development. This has led to a positive marketing image for companies making the switch to resins from renewable resources. This shift of focus is further reinforced by corporations, which are committed to a reduction in their greenhouse gas emissions and product environmental footprints. Here, we present a perspective on the use of renewable materials in durable goods applications and the challenges and advantages associated with the use of renewable materials. Replacement of petroleum-based acoustic foam with that derived from sustainable resources and qualification of thermoplastic polylactic acid blends for enclosure covers has been demonstrated. The technical details of the materials development required for use in durable goods, and their characterization is also discussed.     

Titanium-rich TS-1 zeolite for highly efficient oxidative desulfurization

The exploration of highly efficient catalysts based on nano-sized Ti-rich titanosilicate zeolites with controllable active titanium species is of great importance in zeolite catalytic reactions. Herein, we reported an efficient and facile synthesis of nano-sized Ti-rich TS-1(MFI)zeolites by replacing tetrabutyl orthotitanate(TBOT) with tetrabutyl orthotitanate tetramer(TBOT-tetramer) as the titanium source. The introduced TBOT-tetramer slowed down the zeolite crystallization process, and accordi...     

节能清洁型工厂创建规划

本文介绍济钢"九五"期间实施以优化工艺结构、产品结构和提高资源、能源利用率为核心内容的炼铁全精料、炼钢全精炼、全连铸、轧钢全一火成材和增加高炉喷煤量的"四全一喷",钢渣和含铁尘泥闭路利用、煤气闭路利用、工业用水闭路利用、余热蒸汽闭路利用的"四闭路",实现节能、降耗、减污、增效的有机统一和实际成果.提出了济钢在今后五年创建"节能清洁型工厂"的基本思路和目标,以及实现目标的主要措施.     

Phase change materials for advanced cooling packaging

Controlling the temperature of food packages during transport is needed with the rise of online shopping. During transport, food requires cold temperatures to maintain freshness. A major issue is the undesired warming of food when packages are exposed to warm temperatures on airport tarmacs and temporary unrefrigerated storage during air transportation. To solve this problem, phase change materials (PCMs) can maintain package temperature by changing their phase from liquid to solid or vice versa, to absorb or release latent heat. Although this technology is still not fully commercially viable yet, it has good potential. This article reviews all aspects of PCM packaging, including their classification, technical approaches, and commercial applications, with focus on the direct integration of PCM into food package systems. The article also provides guidelines for future research and reveals aspects that still hinder the full exploitation of PCM in the food packaging industry. To make PCM packaging commercially viable, research needs to consider aspects such as cost, consumer acceptance and confidence, regulatory aspects, e.g., labeling, and multifunctionality.