Catalysts
·
2023
·Vol. 13
·期 7
·1038
·
IF 3.9
Jincheng Wu,Guoguo Liu,Qin Liu,Yajing Zhang,Fu Ding,Kangjun Wang
The hydrogenation of methyl formate to methanol is considered one of the most effective methods for recycling methyl formate products. We recently developed a highly efficient and cost-effective Cu-SiO2catalyst using the ammonia-evaporation (AE) method. The Cu-SiO2-AE catalyst demonstrated superior performance, achieving a methyl formate conversion of 94.2% and a methanol selectivity of 99.9% in the liquid product. The catalyst also displayed excellent stability over a durability test of 250 h. Compared to the commonly used Cu-Cr catalyst in the industry, the Cu-SiO2-AE catalyst exhibited higher conversion of methyl formate and methanol yield under the same reaction conditions. Characterization results revealed a significant presence of Si-OH groups in the Cu-SiO2-AE catalyst. These groups enhanced the hydrogen spillover effect and improved hydrogenation efficiency by preventing sintering during the reaction to stabilize the Cu species. The strategy employed in this study is applicable to the rational design of highly efficient catalysts for industrial applications.Keywords:Cu-SiO2catalyst;hydrogenation of methyl formate;methanol;catalyst stability
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 6
·1-15
·
IF 2.8
Xiao Lijuan,Zhou Jingkai,Yu Zhixuan,Dong Huihao,Chen Yan
In the research of flexible smart electronics, obtaining particular structure electrodes to provide excellent electrochemical performance remains challenging. Here we report the synthesis and characterization of nanocomposite by a two-step method of polypyrrole (PPy) with Co 3 O 4 @SiO 2 in the presence of an oxidizing agent. Co 3 O 4 @SiO 2 was prepared by firing SiO 2 -coated zeolitic imidazolate framework-67 (ZIF-67/SiO 2 ) in a tubular furnace at a high temperature. Subsequently, PPy was coated and dispersed on Co 3 O 4 @SiO 2 by chemical methods at room temperature. In addition, we also explored the optimal ratio experiment of Co 3 O 4 @SiO 2 and PPy. The results show that the specific capacitance of Co 3 O 4 @SiO 2 and Co 3 O 4 @SiO 2 /PPy (2 mL) is 33.36 A/g and 107.7 A/g, at 0.6 A/g current density, indicating that the addition of PPy greatly improves the electrochemical performance of Co 3 O 4 @SiO 2 . This may be due to synergies between Co 3 O 4 @SiO 2 and PPy polymers, and the addition of PPy may help Co 3 O 4 @SiO 2 to construct more ion channels to enhance ion transport. This report will contribute to the development and application of cobalt oxide and silicon-shell electrode materials in the field of energy storage. It is helpful for the development and application of cobalt oxide and silicon-shell structures as electrode materials in the field of energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Friction
·
2024
·Vol. 12
·期 8
·1728-1740
·
IF 6.3
Cui Yuhong,Xue Shenghua,Wang Tiantian,Liu Shujuan,Ye Qian,Zhou Feng,Liu Weimin
Herein, we have prepared SiO 2 particles uploaded MXene nanosheets via in-situ hydrolysis of tetraetholothosilicate. Due to the large number of groups at the edges of MXene, SiO 2 grows at the edges first, forming MXene@SiO 2 composites with a unique core-rim structure. The tribological properties of MXene@SiO 2 as lubricating additive in 500 SN are evaluated by SRV-5. The results show that MXene@SiO 2 can reduce the friction coefficient of 500 SN from 0.572 to 0.108, the wear volume is reduced by 73.7%, and the load capacity is increased to 800 N. The superior lubricity of MXene@SiO 2 is attributed to the synergistic effect of MXene and SiO 2 . The rolling friction caused by SiO 2 not only improves the bearing capacity but also increases the interlayer distance of MXene, avoiding accumulation and making it more prone to interlayer slip. MXene@SiO 2 is adsorbed on the friction interface to form a physical adsorption film and isolate the friction pair. In addition, the high temperature and high load induce the tribochemical reaction and form a chemical protection film during in the friction process. Ultimately, the presence of these protective films results in MXene@SiO 2 having good lubricating properties.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Jiawen Chi,Xueqian Wu,Jiangyan Tao,Xin Min,Zhen Li,Songjian Zhao
Climate warming caused by the yearly rise of CO 2 emissions has posed a great challenge to the survival and development of human beings. In this study, the active component Ni was combined with mesoporous silica (SiO 2 ) to construct a highly dispersed Ni composite silicon-based catalyst (Ni x /Si), which was introduced into the dielectric barrier discharge (DBD) system for the conversion of CO 2 . The XRD and FTIR analyses confirmed that Ni was successfully introduced into the SiO 2 carrier and the SEM results showed that the Ni elements were uniformly distributed. BET and TGA results revealed large specific surface area, stable mesoporous structure, and high thermal stability of the prepared Nix/Si. Further investigation of DBD-coupled Ni x /Si performance for CO 2 conversion showed significant variations based on different Ni loadings, with optimal CO 2 conversion rate, CO yield, and energy efficiency achieved at 3% Ni loading, which increased by 121.8%, 101.5%, and 102.4% respectively compared to the SiO 2 support. During the process of reducing CO 2 , the combination of Ni x /Si and DBD exhibited synergistic effects, with Ni 0 playing a crucial role in the CO 2 reduction. The introduction of Ni x /Si enhances charge transfer in the discharge region, improves CO 2 adsorption, and reduces the dissociation energy of CO 2 bonds. The DBD-coupled Ni x /Si developed by this study offers several advantages including low energy consumption, simple operation, and high efficiency, making it a promising solution for CO 2 treatment.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2019
·
IF 14.695
Shiqun Wu,Xianjun Tan,Juying Lei,Haijun Chen,Lingzhi Wang,Jinlong Zhang
Photodriven nonoxidative coupling of CH4 (NOCM) is a potential alternative approach to clean hydrogen and hydrocarbon production. Herein, a Mott–Schottky photocatalyst for NOCM is fabricated by loading Pt nanoclusters on a Ga-doped hierarchical porous TiO2–SiO2 microarray with an anatase framework, which exhibits a CH4 conversion rate of 3.48 μmol g–1 h–1 with 90% selectivity toward C2H6. This activity is 13 times higher than those from microarrays without Pt and Ga. Moreover, a continuous H2 production (36 μmol g–1) with a high CH4 conversion rate of ∼28% can be achieved through a longtime irradiation (32 h). The influence of Ga on the chemical state of a surface oxygen vacancy (Vo) and deposited Pt is investigated through a combination of experimental analysis and first-principles density functional theory calculations. Ga substitutes for the five-coordinated Ti next to Vo, which tends to stabilize the single-electron trapped Vo and reduce the electron transfer from Vo to the adsorbed Pt, resulting in the formation of a higher amount of cationic Pt. The cationic Pt and electron-enriched metallic Pt form a cationic–anionic active pair, which is more efficient for the dissociation of C–H bonds. However, the presence of too much cationic Pt results in more C2+ product with a decrease in the CH4 conversion rate due to the reduced charge-carrier separation efficiency. This study provides deep insight into the effect of the doping/loading strategy on the photocatalytic NOCM reaction and is expected to shed substantial light on future structural design and modulation.
研究领域:
材料科学
·
催化化学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Luyao Ren,Liangzhong Li,Shuai Chen,Hui Li,Yongdi Liu,Liyang Zhou,Su Guo,YunJiang Yu
In this study, Fe/FeS@SiO 2 yolk-shell particles (Fe/FeS@SiO 2 YSPs) were synthesized, characterized, and applied to tetrabromobisphenol A (TBBPA) removal in simulated groundwater. The X-ray photoelectron spectroscopy, X-ray diffraction, Scanning electron microscopy, transmission electron microscopy and Brunauer Emmett Teller results revealed that Fe/FeS@SiO 2 YSPs possess special structures, including active cores, mesoporous networks, shells, hollow cavities and a large surface area (85 m 2 /g vs. 8 m 2 /g) compared to Fe/FeS. The mobility of the synthesized particles in porous media was simulated with sand column experiments. Fe/FeS@SiO 2 YSPs showed a much better transportability (83.02% of particles successfully transported through the column) than Fe/FeS particles (only 1.68%), related to the better suspension stability and much lower particle surface charge (−22.7 mV vs. −7.6 mV) at neutral pH. Improved TBBPA reduction performance in synthetic solution was observed for Fe/FeS@SiO 2 YSPs over bare Fe/FeS. The transformation pathway of TBBPA was studied in detail, revealing the formation of tri-BBPA, di-BBPA, mono-BBPA and BPA as the main products. In brief, thanks to the hollow mesoporous silica spheres (HMSS) coated on the surface of Fe/FeS particles, Fe/FeS@SiO 2 YSPs showed an enhanced dispersibility, transportability and degradation of TBBPA in simulated groundwater. The results in this study proved that Fe/FeS@SiO 2 YSPs are a promising material for in situ remediation of TBBPA in soil and groundwater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MRS Advances
·
2018
·Vol. 4
·期 7
·359-367
·
IF 0
Chen Chaolang,Weng Ding,Mahmood Awais,Wang Jiadao
In this study, a superhydrophobic and superoleophilic stainless mesh coated with polytetrafluoroethylene/silicon dioxide (PTFE/SiO 2 ) was fabricated through electrostatic self-assembly method followed by sintering treatment. The PTFE was utilized to construct low-surface-energy surface and the SiO 2 nanoparticles were added to enhance its surface roughness. The as-prepared stainless mesh exhibited desirable superhydrophobicity and superoleophilicity with a water contact angle of 152° and oil contact angle of 0°. The coated stainless mesh could separate a variety of oil/water mixtures with high efficiency and it also exhibited good recyclability. Moreover, the corrosion-resistance of stainless mesh was greatly improved by coating it with PTFE. The thermogravimetric analysis (TGA) measurements showed that the coated mesh could withstand high temperature of up to 430°C, indicating excellent thermal-resistance. It is believed that this ultra-robust stainless mesh would have significant potential applications in industry.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
RSC Advances
·
2017
·Vol. 7
·期 12
·7140-7149
·
IF 3.108
Yuchao Xu,Zongzhang Liu,Zheng Han,Minhua Zhang
ZnO promoted ZrO2–SiO2 catalysts synthesized by a sol–gel method were investigated in the two-step ethanol transforming to 1,3-butadiene process. The influence of promoters and the preparation method of the catalysts on the catalytic performance were studied in detail and the reaction conditions were optimized. The as-prepared catalysts were characterized by BET, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Resonance (FT-IR), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy of adsorbed pyridine (Py-IR) and temperature-programmed desorption of NH3 (NH3-TPD). ZnO added ZrO2–SiO2 catalysts show the best catalytic activity and the catalysts prepared by the hybrid sol–gel method were superior to those prepared by the sol–gel coupled with impregnation method. The addition of promoters in the ZrO2–SiO2 system decreased the total acidity and lowered the selectivity to dehydration products. The best performance with ethanol/acetaldehyde conversion of 40.7% and 1,3-butadiene selectivity of 83.3% was reached at 310 °C, ethanol/acetaldehyde mole ratio of 3.5 and WHSV of 1.4 h−1 using a 0.5 wt% ZnO doped ZrO2–SiO2 catalyst.
研究领域:
催化化学
·
材料科学
·
能源化工
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2023
·
IF 9
Run Qi,Zhaohao Li,Hongyuan Zhang,Hongming Fu,Heng Zhang,Dan Gao,Haiping Chen
Membrane absorption is a promising CO 2 capture technology, which is limited by the high cost of membrane materials. Coal fly ash (CFA)-based ceramic membrane as an alternative material for membrane modules can effectively reduce the preparation cost. In this study, CFA-based ceramic membrane with superhydrophobic properties is prepared by depositing SiO 2 nanoparticles and grafting 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (POTS). Characters including pore size distribution, porosity and N 2 flux of superhydrophobic membrane are performed. The superhydrophobic modified ceramic membrane is applied to CO 2 capture experiments using ethanolamine (MEA) solution as the absorbent. The result shows that the contact angle of the modified ceramic membrane reaches 155.0°, which significantly improves the anti-wetting properties of the membrane surface . The CO 2 capture experiment demonstrates a maximum capture efficiency of 97.45% and a mass transfer rate of 21.17 mol/(m 2 ·h). In addition, the superhydrophobic modified ceramic membrane exhibits excellent thermal and chemical stability, sustaining high performance even after 8 h of continuous operation. This study provides the theoretical and empirical foundation for the application of CFA-based superhydrophobic ceramic membranes in CO 2 capture.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 37
·e202300997
·
IF 2.1
Yingying Li,Jiafei Wang,Xiang Wan,Qishu Qu
Graphical SiO 2 /graphene spheres with intercalated structure and dendritic pores were prepared as supports by a one-step hydrothermal method, and then TiO 2 was coated on them to obtain SiO 2 /graphene@TiO 2 composites (SGT). After 90 min of visible light irradiation, the degradation rate of RhB by SGT catalyst was 68.9 %, which was significantly higher than that of P25 by 39.3 %. The use of TiO 2 /graphene composites as catalysts for photodegradation of dyes has been widely investigated. TiO 2 /graphene composites are usually obtained by coating TiO 2 on the surface of pre-prepared graphene. However, graphene is prone to curling and stacking, which makes it difficult to uniformly coat TiO 2 on its surface, resulting in poor photocatalytic performance. In this paper, a non-conventional approach to prepare TiO 2 /graphene nanocomposites based on the use of porous SiO 2 /graphene spheres as supports is presented. SiO 2 /graphene spheres with intercalated structure and dendritic pores were prepared as supports by a one-step hydrothermal method. Then, TiO 2 was coated into the pores of SiO 2 /graphene spheres by sol-gel method to obtain SiO 2 /graphene@TiO 2 composites (SGT). After 90 min of visible light irradiation, the degradation rate of RhB by SGT catalyst was 68.9 %, which was significantly higher than that of P25 by 39.3 %. A mechanism of the RhB removal by the SGT composites was proposed.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2018
·Vol. 58
·期 12
·2143-2148
·
IF 1.551
Juan Chen,Wenbo Zhang,Heyi Ge,Juanjuan Tan,Jianye Liu
The hybrids of graphene oxide (GO) encapsulated nano-SiO 2 (SiO 2 -GO) were introduced into phenolic resin (PR) to enhance thermal stability of PR. The effect mechanism was investigated in detail. Through electrostatic self-assembly method, the SiO 2 nanoparticles were evenly distributed onto the surface of GO. This structure could not only prevent the aggregation of nano-SiO 2 , but also alleviate the phenomenons of crimp and stack for GO sheets in PR. Nano-SiO 2 and GO showed elaborate synergistic effect on thermal stability of PR. Compared with the pristine PR, the 2 wt% SiO 2 -GO/PR composite showed higher T 5% , T 10% , and T dmax , which were increased by 65.39, 62.23, and 23.17°C, respectively. And the char yield at 800°C increased from 64.78% to 69.38%. Thus, SiO 2 -GO hybrids can facilitate the application of PR in the fields of heat insulation and ablation resistance. POLYM. ENG. SCI., 58:2143–2148, 2018. © 2018 Society of Plastics Engineers
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Chenguang Li,Junbin Sun,Weihong Lu
The corrosion caused by air sediments comprising CaO-MgO-Al 2 O 3 -SiO 2 (CMAS) poses a notable challenge to thermal/environmental barrier coatings as engine service temperatures continue to rise. In this study, three types of Y 2 O 3 -SiO 2 binary compound ceramic bulks—Y 2 SiO 5 , Y 2 SiO 5 -Y 2 Si 2 O 7 and Y 2 Si 2 O 7 —with molar ratios of Y 2 O 3 :SiO 2 of 1:1, 1:1.5, and 1:2, respectively, were prepared and subjected to CMAS corrosion at 1250 °C and 1350 °C for durations ranging from 1 to 10 h. The corrosion products and cross-sectional morphologies of the samples were characterized using X-ray diffraction and scanning electron microscope. The results demonstrate that the material composition determines its CMAS corrosion behavior. Y 2 SiO 5 , with higher Y 2 O 3 content, consumes more CaO to form Ca 2 Y 8 (SiO 4 ) 6 O 2 , thereby reducing the CaO content and increasing the viscosity of the residual CMAS melt. This process inhibits further CMAS penetration. The findings highlight a novel strategy to improve CMAS corrosion resistance by modifying the CMAS composition and reducing its penetration capability.
研究领域:
材料科学
·
无机非金属材料
·
高温腐蚀与防护
·
陶瓷基复合材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）