Sodium-ion batteries (SIBs) attract more attention because of sodium’s abundant availability, affordable price, and potential to be an effective anode material. Meanwhile, carbon-based materials ...provide the most promising anode materials. Because of the large radius of sodium ions, SIBs do not exhibit favorable electrochemical performance. Introducing heteroatoms into the carbon-lattice is an effective strategy to enlarge the interlayer space of carbon-based materials which can improve carbon’s electrochemical performance. In addition, anode materials with a surface-induced capacitive process can enhance the SIB’s electrochemical performance because its capacitive process increases the kinetics of ion diffusion. Here, we describe an SIB’s anode material containing nitrogen and sulfur co-doped graphene sheets denoted as poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT)/reduced graphene oxide (RGO) which are synthesized via carbonization of PDMcT polymerized on the surface of GO. PDMcT/RGO exhibited high capacities (240 mA h g–1 at 500 mA g–1), improved rate performance (144 mA h g–1 at 10 A g–1), and good cycling stability (153 mA h g–1 after 5000 cycles at 5000 mA g–1). These unique results are attributed to the enlarged interlayer spacing and electronic conductivity from the heteroatoms which facilitate the sodium ion’s insertion and electron transport. These results represent that PDMcT/RGO is a great potential anode material for SIBs.
China's rapid urbanization, large population, and increasing consumption of calorie-and meat-intensive diets, have resulted in China becoming the world's largest source of ammonia (NH3) emissions ...from livestock production. This is the first study to use provincial, condition-specific emission factors based on most recently available studies on Chinese manure management and environmental conditions. The estimated NH3 emission temporal trends and spatial patterns are interpreted in relation to government policies affecting livestock production. Scenario analysis is used to project emissions and estimate mitigation potential of NH3 emissions, to year 2030. We produce a 1km×1km gridded NH3 emission inventory for 2008 based on county-level activity data, which can help identify locations of highest NH3 emissions. The total NH3 emissions from manure generated by livestock production in 2008 were 7.3TgNH3·yr−1 (interquartile range from 6.1 to 8.6TgNH3·yr−1), and the major sources were poultry (29.9%), pigs (28.4%), other cattle (27.9%), and dairy cattle (7.0%), while sheep and goats (3.6%), donkeys (1.3%), horses (1.2%), and mules (0.7%) had smaller contributions. From 1978 to 2008, annual NH3 emissions fluctuated with two peaks (1996 and 2006), and total emissions increased from 2.2 to 7.3Tg·yr−1 increasing on average 4.4%·yr−1. Under a business-as-usual (BAU) scenario, NH3 emissions in 2030 are expected to be 13.9TgNH3·yr−1 (11.5–16.3TgNH3·yr−1). Under mitigation scenarios, the projected emissions could be reduced by 18.9–37.3% compared to 2030 BAU emissions. This study improves our understanding of NH3 emissions from livestock production, which is needed to guide stakeholders and policymakers to make well informed mitigation decisions for NH3 emissions from livestock production at the country and regional levels.
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•1km×1km gridded NH3 emissions from China's livestock manure were estimated.•Provincial condition-specific emission factors and county-level activity data were used.•Emission trends and patterns were interpreted in light of government policies.•NH3 emissions were projected to year 2030 under six mitigation scenarios.•Low NH3 application was the most effective scenario for NH3 mitigation.
Compressible and ultralight all-carbon materials are promising candidates for piezoresistive pressure sensors. Although several fabrication methods have been developed, the required elasticity and ...fatigue resistance of all-carbon materials are yet to be satisfied as a result of energy loss and structure-derived fatigue failure. Herein, we present a two-stage solvothermal freeze-casting approach to fabricate all-carbon aerogel modified graphene aerogel (MGA) with a multi-arched structure, which is enabled by the in-depth solvothermal reduction of graphene oxide and unidirectional ice-crystal growth. MGA exhibits supercompressibility and superelasticity, which can resist an extreme compressive strain of 99% and maintain 93.4% height retention after 100 000 cycles at the strain of 80%. Rebound experiments reveal that MGA can rebound the ball (367 times heavier than the aerogel) in 0.02 s with a very fast recovery speed (∼615 mm s–1). Even if the mass ratio between the ball and aerogel is increased to 1306, the ball can be rebound in a relatively short time (0.04 s) with a fast recovery speed (∼535 mm s–1). As a result of its excellent mechanical robustness and electrical conductivity, MGA presents a stable stress–current response (10 000 cycles), tunable linear sensitivity (9.13–7.29 kPa–1), and low power consumption (4 mW). The MGA-based wearable pressure sensor can monitor human physiological signals, such as pulses, sound vibrations, and muscular movements, demonstrating its potential practicability as a wearable device.
Increasing the cracking ability of catalyst by adjusting its surface acid property is of great significance for oil refining industry. The effects of boric acid on the structure and surface acidity ...of ultra stabilized Y (USY) and FCC equilibrium catalyst during the modification were investigated. The structural and surface properties of the prepared samples were characterized by low-temperature N2 sorption, XRD, 27Al and 29Si MAS NMR, and FTIR using pyridine probe molecule. Modified USY and equilibrium catalyst possessed reduced Lewis acid sites. The Brönsted/Lewis acid ratios of USY increased from 0.64 to 1.56 after modification, at the same time, the microporous surface areas increased, due to the nonframework and framework dealumination during the modification. The catalytic cracking tests were performed on a bench-scale micro reactor at 500 °C and atmospheric pressure, using n-dodecane as a modeling reactant and vacuum gas oil as conventional feedstock. The results showed that modified samples with high Brönsted acid sites had better cracking abilities and increased hydrogen transfer activity than raw samples.
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•Zeolite Y and equilibrium catalyst were modified using boric acid in hydrothermal conditions.•The modified USY and equilibrium catalyst possess increased Brönsted/Lewis acid ratio.•Modified catalysts have good performances in catalytic cracking of hydrocarbons.•The coke formation in catalytic cracking is related with the hydrogen transfer rate.
Improving propylene selectivity and the lifetime of ZSM-5 catalyst is of great significance for methanol to propylene (MTP) reaction. Hierarchical ZSM-5 zeolites were synthesized by a two-stage ...crystallization method using glucose as a second template. The structural and surface properties and the morphologies of the prepared samples were characterized by low-temperature N2 sorption, XRD, 27Al and 29Si NMR, FTIR using pyridine probe molecule, NH3-TPD, SEM, and TEM analysis. The two-stage glucose-assisted crystallized ZSM-5 zeolites exhibited large prismatic crystallites, increased intracrystalline mesopores, and reduced acid amount and acid strength, compared with the conventional one-stage crystallized ZSM-5. Methanol to propylene (MTP) reaction at 450 °C and methanol WHSV of 3.8 h−1 revealed that the newly prepared ZSM-5 catalyst, such as ZSM-5-T3, exhibited highest propylene selectivity of 45.2%, propylene to ethylene ratio of 8.4, and C2=-C4= selectivity of 63.9%.
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•Hierarchical ZSM-5 zeolite was prepared by a two-stage crystallizing method using glucose as a second template.•Newly prepared ZSM-5 zeolite had large prismatic crystallites and reduced acid amount and strength.•Newly prepared ZSM-5 catalyst exhibited highest propylene selectivity, propylene/ethylene ratio, and C2=-C4= selectivity.
Fundamental studies describing the impact of carbon’s physical and chemical properties on NO oxidation allow for the development of catalysts tailored specifically for abating emissions of nitrogen ...oxides. Here, we show that acidic oxygen functional groups are developed on activated carbon fiber cloth during carbon-catalyzed NO oxidation. Reaction and thermal desorption cycle experiments demonstrate the continuous addition of oxygen to carbon as carbonyl and carboxyl functional groups. After four cycles, the oxygen content of carbon increased by 280%. There is also a 65% reduction in the time required to release NO2 from the carbon surface, allowing the reaction to achieve steady-state NO conversion 45% faster. The steady-state NO oxidation rate remains constant during the four cycles (48.5±1.6μmol/h), which is attributed to stable physical properties of carbon during the cycles. Oxygen groups added during the cycles, therefore, have no detectable impact on the overall conversion of NO over carbon, but control the pathway to achieving stable conditions. Carbon catalysts prepared with acidic oxygen functionalities are promising as NO oxidation catalysts, as confirmed with NO2 and nitric acid treatments. It is proposed that carbon’s chemical properties impact NO oxidation kinetics while carbon’s physical properties impact the steady-state NO oxidation rate.
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► Natural N-containing carbon with 3D aperiodic hierarchical structure. ► Prepared from ocean pollutant, easing CO2 burden via hydrothermal carbonization. ► A good performance for CO2 ...sorption and facile regeneration were achieved. ► A Piecewise model to analyze adsorption kinetics.
Nitrogen-containing porous carbon was synthesized from an ocean pollutant, Enteromorpha prolifera, via hydrothermal carbonization and potassium hydroxide activation. Carbons contained as much as 2.6% nitrogen in their as-prepared state. Physical and chemical properties were characterized by XRD, N2 sorption, FTIR, SEM, TEM, and elemental analysis. The carbon exhibited a hierarchical structure with interconnected microporosity, mesoporosity and macroporosity. Inorganic minerals in the carbon matrix contributed to the development of mesoporosity and macroporosity, functioning as an in situ hard template. The carbon manifested high CO2 capacity and facile regeneration at room temperature. The CO2 sorption performance was investigated in the range of 0–75°C. The dynamic uptake of CO2 is 61.4mg/g and 105mg/g at 25°C and 0°C, respectively, using 15% CO2 (v/v) in N2. Meanwhile, regeneration under Ar at 25°C recovered 89% of the carbon's initial uptake after eight cycles. A piecewise model was employed to analyze the CO2 adsorption kinetics; the Avrami model fit well with a correlation coefficient (R2) of 0.98 and 0.99 at 0°C and 25°C, respectively.
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