Few-layered hexagonal boron nitride nanosheets stabilized Pt NPs for oxidation promoted adsorptive desulfurization of fuel oil

A few-layered hexagonal boron nitride nanosheets stabilized platinum nanoparticles(Pt/h-BNNS)is engineered for oxidation-promoted adsorptive desulfurization(OPADS)of fuel oil.It was found that the few-layered structure and the defective sites of h-BNNS not only are beneficial to the stabilization of Pt NPs but also favor the adsorption of aromatic sulfides.By employing Pt/h-BNNS with a Pt loading amount of 1.19 wt%as the active adsorbent and air as an oxidant,a 98.0%sulfur removal over dibenzothiophene(DBT)is achieved along with a total conversion of the DBT to the corresponding sulfones(DBTO_(2)).Detailed experiments show that the excellent desulfurization activity originates from the few-layered structure of h-BNNS and the high catalytic activity of Pt NPs.In addition,the OPADS system with Pt/h-BNNS as the active adsorbent shows remarkable stability in desulfurization performance with the existence of different interferents such as olefin,and aromatic hydrocarbons.Besides,the Pt/h-BNNS can be recycled 12 times without a significant decrease in desulfurization performance.Also,a process flow diagram is proposed for deep desulfurization of fuel oil and recovery of high value-added products,which would promote the industrial application of such OPADS strategy.

Hexagonal boron nitride:A metal-free catalyst for deep oxidative desulfurization of fuel oils

Oxidative desulfurization(ODS)has been proved to be an efficient strategy for the production of clean fuel oil.Numerous metal-based materials have been employed as excellent ODS catalysts,but being hindered by their high-cost and potential secondary pollution.In this work,we employed graphene analogous hexagonal boron nitride(h-BN)as a metal-free catalyst for ODS with hydrogen peroxide(H2O2)as the oxidant.The h-BN catalyst was characterized and proved to be a few-layered structure with relatively high specific surface areas.The h-BN catalyst showed a 99.4%of sulfur removal in fuel oil under the optimized reaction conditions.Besides,the h-BN can be recycled for 8 times without significant decrease in the catalytic performance.Detailed mechanism analysis found that it is the boron radicals in h-BN activated H2O2 to generate·OH species,which can readily oxidize sulfides to corresponding sulfones for separation.This work would provide another choice in choosing metal-free catalysts for ODS.

3D-printing of integrated spheres as a superior support of phosphotungstic acid for deep oxidative desulfurization of fuel

Construction of catalysts with integral structure for oxidative reaction process is an essential promotion to catalysts in industrial application.In this work,a 3D printing method was employed to prepare 3D printed spheres(3D-PSs),followed by carbonization to form 3D carbon spheres(3D-CSs).Then,a 3D-CSs supported phosphotungstic acid(HPW/3D-CSs)was prepared for deep oxidative desulfurization.Compared with traditional powder catalysts,the as-prepared catalyst is easy to be operated and separated from oil products.The supported catalyst possesses excellent catalytic performance and the removal of DBT,4-MDBT and 4,6-DMDBT in fuel oil,reaching^100%of sulfur removal.The effects of various experimental parameters on desulfurization efficiency were considered to optimize reaction conditions.Moreover,the catalyst shows excellent thermal and chemical stability,with no obvious decrease in desulfurization activity after 5 cycles.GC–MS analysis indicates DBT sulfone was the solely oxidized product of DBT.

中国西南地区2007年-2011年男性乳腺癌发生率(英文)

Objective: Male breast cancer is a rare disease with an incidence of about 1% of breast cancers in USA, but relatively lack of the information of male breast cancer in China, especially in Southwest of China, led us to study its incidence trends. Methods: Chongqing is one of the biggest and the most important areas that is located in Southwest of China. There are around 31.4 million people who live in approximate 82 402.95 km2area of Chongqing. Data about breast cancer patients registered in the Center for Disease Prevention and Control of Chongqing(China) were statistically collected from 187 hospitals, about 58 hospitals in city and 129 hospitals in country, and over 6.2 million people were studied every year. It was tried to represent all the people in villages and cities in Chongqing, China. Results: The incidence of male breast cancer in Southwest of China ranged from 0.34/100 000 to 1.45/100 000 between 2007 and 2011, while the incidence of female breast cancer ranged from 15.40/100000 to 21.66/100000 at the same time. The rate of male breast cancer to female breast cancer ranged from 0.02:1 to 0.07:1, male breast cancer accounted for 1.96% to 6.5%(with the mean value of 2.9%) of breast cancers in Southwest of China from 2007 to 2010. Conclusion: In Southwest of China male breast cancer accounts for about 2.9% of breast cancers which is higher than that in United States. It is important for policy makers and health manager to seriously consider breast cancer in future plan in Southwest of China.

Engineering 3D-printed aqueous colloidal ceramic slurry for direct ink writing

The construction of rapid prototyping for structured ceramics has a promoting effect on potential applications.In this work,engineering slurry with different formulations were used to develop aqueous colloidal ceramic slurry for direct ink writing(DIW).Optimized slurry of Formulation 5 possessed good printing effect for DIW with stable mechanical properties.Related characteristics,including shrinkage,compressive strength,rheological behavior,and chemical property,were also examined.DIW ceramics prepared from optimized slurry can be preliminarily applied to adsorption of Rhodamine B and chlortetracycline,and possessed the advantages of easy separation and operation compared with powder adsorbents.This work provides a strategy for the design of 3D-printed kaolin ceramic slurry,and also extends to potential application in adsorption.

Stable Au nanoparticles confined in boron nitride shells for optimizing oxidative desulfurization

Supported gold(Au)nanocatalysts have long played an important role in numerous heterogeneous catalysis.However,the dominant difficulty of poor thermodynamic stability hampers its practical application.Herein,a core–shell structured Au nanocatalyst with Au nanoparticles(NPs)confined in boron nitride(BN)shells is proposed for enhanced thermodynamic stability.The two-dimensional porous structure of BN not only functions as a physical separator for the sintering resistance of Au NPs,but also provides a microchannel for catalytic reaction substrates.Besides,owing to the confinement effect,a strengthened interaction between well-designed Au NPs and the BN can be expected,which further boosts the stability and catalytic activity.Detailed experiments show that a proper BN shell thickness is important to maintain the balance between the sintering resistance and catalytic activity.A significantly boosted performance of 97.2%conversion in oxidative desulfurization(ODS)was obtained with a proper number of BN coating layers,outperforming the one with a thicker BN shell.Moreover,the recyclability of the prepared catalyst was investigated with no obvious decrease in catalytic performance after 10 runs,greatly higher than that without a BN shell,suggesting excellent durability.

Engineering the electronic and geometric structure of VO_(x)/BN@TiO_(2)heterostructure for efficient aerobic oxidative desulfurization

Particle size governs the electronic and geometric structure of metal nanoparticles(NPs),shaping their catalytic performances in heterogeneous catalysis.However,precisely controlling the size of active metal NPs and thereafter their catalytic activities remain an affordable challenge in ultra-deep oxidative desulfurization(ODS)field.Herein,a series of highly-efficient VO_(x)/boron nitride nanosheets(BNNS)@TiO_(2)heterostructures,therein,cetyltrimethylammonium bromide cationic surfactants serving as intercalation agent,BNNS and MXene as precursors,with various VO_(x)NP sizes were designed and controllably constructed by a facile intercalation confinement strategy.The properties and structures of the prepared catalysts were systematically characterized by different technical methods,and their catalytic activities were investigated for aerobic ODS of dibenzothiophene(DBT).The results show that the size of VO_(x)NPs and V^(5+)/V^(4+)play decisive roles in the catalytic aerobic ODS of VO_(x)/BNNS@TiO_(2)catalysts and that VO_(x)/BNNS@TiO_(2)-2 exhibits the highest ODS activity with 93.7%DBT conversion within 60 min under the reaction temperature of 130℃and oxygen flow rate of 200 mL·min-1,which is due to its optimal VO_(x)dispersion,excellent reducibility and abundant active species.Therefore,the finding here may contribute to the fundamental understanding of structure-activity in ultradeep ODS and inspire the advancement of highly-efficient catalyst.