Search

In this study, porous amorphous SiO2−Al2O3 (ASA(Si/Al=x)) with different Si/Al ratios was synthesized by gel‐gel method, and used to catalyze green renewable energy source γ‐valerolactone (GVL) to butene. Research indicated that all prepared catalysts had large amounts of disordered mesoporous with the pore size in range of 2–13 nm. For the optimal ASA(Si/Al=20) catalyst, its specific surface area is 430.20 m2 g−l and pore size is about 8.13 nm. Due to the presence of suitable Al species, ASA(Si/Al=20) has the largest Brønsted/Lewis ratio and 0.5554 mmol g−1 weak acid site content. Under the optimized reaction conditions, 90 % butene yield can be obtained in 180 min at 300 °C. In addition, the regeneration performance of the ASA(Si/Al=20) catalyst is also satisfactory, and the yield of butene can be above 60 % after 5th cycles. After activation, the spent catalyst can be regenerated, and about 78 % butene yield can be also obtained. [ABSTRACT FROM AUTHOR]

A manganese dioxide and ferric hydroxide doped KIT-6 adsorbent (8MnO2/FeOOH/KIT-6) was prepared and employed for As(III) adsorption. The studies indicated that the large surface area, particular pore structure and the synergy interaction between FeOOH and MnO2 endow the adsorbent with excellent adsorption performance. The adsorption rate of 8MnO2/FeOOH/KIT-6 for As(III) could reach 92% when the As(III) initial concentration was 20 mg L−1 and the adsorbent dose was 1 g L−1, at pH 1. During five consecutive cycles, 8MnO2/FeOOH/KIT-6 exhibited good stability, and the adsorption rate was consistently above 90%. The adsorption capacity of the 8MnO2/FeOOH/KIT-6 for As(III) was 39.77 mg g−1 when 10 mg of adsorbent and 10 mL of As(III) ion solution (20 mg L−1) were used at pH 1 and 303 K. The adsorption of As(III) on 8MnO2/FeOOH/KIT-6 was a spontaneous process and in line with the pseudo-second-order kinetic model. More importantly, 8MnO2/FeOOH/KIT-6 showed excellent selectivity in a complex system, for example Cl−, NO3−, SO42−, SiO32− or Ge4+ coexisting with As(III) in wastewater. [ABSTRACT FROM AUTHOR]

Form‐stable phase change materials (PCMs) have great potential to regulate the unbalanced heat demand and supply, yet most of the PCMs are in powder, plate, or bulk rigid forms, difficult to adhere to the heat source or target substrates. Herein, PCMs coatings based on reactive poly(ethylene glycol) (RPEG) are developed for direct thermal energy exchange and storage. RPEG with highly reactive silanol groups is obtained by reaction of PEG with 3‐isocyanatopropyltriethoxysilane (IPTS), followed by hydrolyzation in weak acid. Cross‐linked PCMs coatings are obtained on various substrates, including cotton fabric, wood, tinplate, and even irregular objects. The coatings show obvious solid‐solid phase transition properties and high energy storage densities (142.8 J g−1). Multi‐walled carbon nanotubes (MWCNTs) are further doped into the coatings aided by a self‐cross‐linkable dispersant. The composite coatings exhibit excellent high‐temperature form stability and rapid thermal exchange properties owing to the formation of the cross‐linked network between RPEG and MWCNTs. Thermal regulation clothes are prepared by a spray coating method, which show no performance deterioration after washing three times, indicating good washing durability. [ABSTRACT FROM AUTHOR]

A novel preparative approach for promising cathode materials for capacitive deionization (CDI) is proposed. Several 3D Na4Ti9O20/N-doped carbon composite materials (3D NTO/N-C-x, x represents the hydrothermal reaction time) with high surface area are synthesized by pyrolysis of Ti-based metal–organic frameworks (Ti-MOFs) and a subsequent hydrothermal treatment strategy. Notably, the intrinsic interfacial interaction of the optimized 3D NTO/N-C-2 facilitates the synergy of the internal driving field and condensed phase interface, which is greatly beneficial to obtain more active sites for sodium ion storage and improved storage capacity (249 F g−1 at 1 A g−1). Furthermore, an all-faradaic-type 3D NTO/N-C-2//Ag@rGO full desalination cell shows high salt adsorption capacity (59.3 mg g−1) and stable cycling desalination ability (95% capacity retention rate over 20 cycles at 1.4 V). In addition, the mechanism of the zwitterion removal/release of the desalination cell is thoroughly investigated by electrochemical measurement. This work not only provides a reasonable strategy to establish cathode materials for CDI, but also may trigger the rapid development of Ti-based electrode materials in many frontier fields. [ABSTRACT FROM AUTHOR]

In this article, a novel Mo(VI)-imprinted adsorbent based on brown algae (Mo-PVA-SA-I) was synthesized through an ion-imprinting technique in combination with surface imprinting and polymer crosslinking. As the template ion, H3Mo7O243 – also acts as the cross-linker to effectively decrease the space and distance between the molecular chains and make the algae form a uniform size of porous structure, it can be used to construct Mo(VI)-matching specific "cavities" after being eluted. Results indicated that the Mo(VI)-imprinted algae have a poor adsorption capacity for its coexisting ions, such as rhenium, copper, iron, zinc, and manganese metal ions at pH 3, while it exhibits apparently higher selective recognition ability for Mo(VI) than the non-imprinted absorbent (Mo-PVA-SA-N). In addition, the prepared Mo(VI)-imprinting algae was equipped with a high adsorption capacity of 114.40 mg·g–1 for Mo(VI). The excellent adsorption performance of this novel Mo-PVA-SA-I adsorbent has been proven to be due to electrostatic attraction between the C = N+–H imine groups and H3Mo7O243 – in the "cavities" by both FT-IR and XPS analysis. As a result, this novel and environment-friendly Mo(VI)-imprinted algae will be a promising candidate for recovering Mo(VI) from industrial wastewater. [ABSTRACT FROM AUTHOR]

Efficient recovery of rare scattered metal Re(VII) from various resources is a prerequisite due to its important application. Herein, a type of novel nanofibrous membrane, 0.4P(Ph-3MVIm-Br)-3PVP/2TPU, is successfully prepared by electrospinning, where poly(ionic liquid) P(Ph-3MVIm-Br) is incorporated and could supply more adsorption sites. Meanwhile, PVP (polyvinyl pyrrolidone) and TPU (thermoplastic polyurethane) ensured the water flux and the structural stability of the membrane. The nanofibrous membrane exhibited a high adsorption capacity for ReO 4 −, which can reach 128 mg g−1 at pH 5. Its water flux is as high as 433 L m−2 h−1 at 0.4 g of poly(ionic liquid) addition, membrane thickness of 20 μm, and pressure of 1 bar. Furthermore, 0.4P(Ph-3MVIm-Br)-3PVP/2TPU nanofibrous membrane can remove 91.7% of ReO 4 − within 30 min. After 9 times recycling, the adsorption efficiency of the membrane can still maintain more than 90%. Dynamic ReO 4 − removal with 0.4P(Ph-3MVIm-Br)-3PVP/2TPU after one cycle was accomplished with a breakthrough volume of 24 mL ReO 4 − solution (feed 10 mg L−1, 100 mg membrane). The exchange of ReO 4 − and Br− of poly(ionic liquid) mostly promote the adsorption of ReO 4 −. Moreover, the structure of the membrane has excellent selectivity, mechanical performance, strong acid and alkali resistance stability, which endow the membrane easy to operate in practical applications. [Display omitted] • Nanofibrous membrane can remove 91.7 % of ReO 4 − within 30 min. • It has a great adsorption capacity of 128 mg g−1 for ReO 4 − at pH 5. • It has a good selectivity for ReO 4 − in the presence of SO 4 2− or NO 3 −. • It unfolds prominent regeneration ability after nine consecutive cycles. • It can achieve a water flux of 433 L m−2 h−1. [ABSTRACT FROM AUTHOR]

In this paper, Gd-promoted Co 3 O 4 catalysts were prepared via a facile coprecipitation method for low-temperature catalytic N 2 O decomposition. Due to the addition of Gd, the crystallite size of Co 3 O 4 in the Gd 0.06 Co catalyst surprisingly decreased to 4.9 nm, which is much smaller than most additive-modified Co 3 O 4 catalysts. This huge change in the catalyst's textural structure endows the Gd 0.06 Co catalyst with a large specific surface area, plentiful active sites, and a weak Co-O bond. Hence, Gd 0.06 Co exhibited superior activity for catalyzing 2000 ppmv N 2 O decomposition, and the temperature for the complete catalytic elimination of N 2 O was as low as 350 °C. Meanwhile, compared with pure Co 3 O 4 , E a decreased from 77.4 to 46.8 kJ·mol -1 and TOF of the reaction increased from 1.16 × 10 -3 s -1 to 5.13 × 10 -3 s -1 at 300 °C. Moreover, Gd 0.06 Co displayed a quite stable catalytic performance in the presence of 100 ppmv NO, 5 vol % O 2 , and 2 vol % H 2 O.