We began by collecting Mӧss reference spectra for the as-received tin chlorides, crystalline SnCl 4 ·5H 2 O and crystalline SnCl 2 ·2H 2 O, and the same starting materials dissolved in 7.5 M HCl (the electrolyte solution used for the synthesis of the Pt nanoparticles). High concentrations of HCl at acidic pH have previously been …
The O adsorption energy on the Pt top site (−182 kJ.mol −1) with a Pt−O bond length of 1.79 Å is twice stronger than that on the Sn top site (−85 kJ.mol −1) with a Sn−O bond length of 1.87 Å.This result which does not follow the intuitive expectation based on electronegativity of Pt and Sn elements, highlights that the specific behavior of such …
In order to investigate the local structure of active catalysts (Pt–Sn/SiO2-PC, Pt–Sn/SiO2-DR) and be certain of relevant preparation processes, we also performed the XAS …
The experimental results, i.e. enthalpies of formation of liquid, solid and two-phase alloys are presented in Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6.They exhibit a very strong interaction in (Pt–Sn) alloys (all values of Δ mix H m ° are very negative). At the start of a series (x Pt =0) a liquid phase is formed.The occurrence of a breakpoint in the enthalpy …
Relative to the Cr-based catalysts, Pt-based catalysts in which Pt nanoparticles (NPs) supported on Al 2 O 3 and modified by the addition of a post-transition metal such as tin (Sn) exhibit higher selectivity. …
This study focused on reducing the catalyst cost and improving the performance of cathode in single chamber microbial fuel cell (SCMFC). Cost-effective Pt 7 Sn 3 P/C and PtSn (with different Pt/Sn atomic ratios) catalysts were investigated for the oxygen reduction reaction (ORR) in SCMFCs with air cathode. The morphology, surface …
The influences of Pt/Sn ratios were investigated. Changing the Pt/Sn ratios influences the interaction between Pt and Sn. The catalyst with a Pt/Sn ratio of 1:2 possesses the highest interaction between Pt and Sn. The best catalytic performance was obtained for the Pt 1 Sn 2 /DMSN catalyst with an initial propane conversion of 34.9%. The good ...
Download PDF. back. In this work, Pt-SnO2 heteroaggregate nanocatalysts were synthesized by in situ transformation of Pt@Sn core–shell nanoparticles and their …
Poly(vinyl pyrrolidone) with a M w of 1.3 × 106 g/mol (PVP) or 4 × 104 g/mol (PVPLow) was used as a polymer to fabricate PVP–Pt, PVP–Pt–Cu, and PVPLow–Pt–Sn composite fibers by electrospinning. The effect of varying the electrospinning conditions on the fiber morphology was investigated, and the solution composition and electrospinning …
"Over hợp" với các tín đồ nhà Honda - Alo hotline 1800 1165 hoặc 0375 83 79 79 ngay để nhận ưu đãi lớn và nhanh tay chốt deal hời cccm nhé =))). Honda Ôtô Hà Nội - Mỹ Đình · Original audio
Additionally, we found that atomic ordering in Pt–Sn nanoalloys is driven by the balance between the surface segregation energy of Sn atoms and the energy of …
The TOFs of these Pt-Sn iNPs in furfural hydrogenation were also calculated as shown in Fig. S8. The Pt-Sn iNPs have 2 to 7-fold higher TOFs than pure Pt exemplifying the promotion effect of bimetallic Pt-Sn in furfural hydrogenation. The Pt-rich Pt 1.2 Sn catalysts have similar TOFs (0.20 s −1) regardless of the reduction temperatures.
The Pt-Sn bimetallic catalyst (PtSn0.25/T) prepared with 0.25 wt% tin, followed by H 2 pre-treatment, demonstrated beneficial properties in terms of CO chemisorption and O 2 dissociative adsorption. Theoretical investigation for the adsorption behavior of the reactant on Pt/TiO 2 and PtSn/TiO 2 was in line with the experimental …
With the growing global propylene demand, propane dehydrogenation (PDH) has attracted great attention for on-purpose propylene production. However, its industrial application is limited …
Pt–Sn–K/q-Al2O3 for propane dehydrogenation† Yu Shi, ab Xianru Li,ab Xin Rong,ab Bin Gu,ab Huangzhao Weia and Chenglin Sun*a A study on the performance of Pt(0.3 wt%)Sn(0.2 wt%)K(0.5 wt%) catalysts supported on four different q-Al 2O 3 for propane dehydrogenation is reported in this study. The q-Al 2O 3 used as supports were
Combining the core-shell structure with the optimization of surface composition and structure in the shell is a fantastic strategy to enhance the electrocatalytic performances. Here, we synthesized trimetallic Au@PtxSny core-shell nanoparticles (NPs) with tunable composition and structure of Pt-Sn alloyed shells. Impressively, the …
We report that silica-supported platinum-tin (Pt 1 Sn 1) nanoparticles (<2 nanometers in diameter) can operate as a PDH catalyst at thermodynamically limited …
Characterization of PtSn clusters in MFI zeolite. Initially, a K-PtSn@MFI-Air sample (containing 0.4 wt% Pt, 0.9 wt% Sn and 0.6 wt% K) was prepared by a one-pot synthesis according to our ...
The stability and atomic ordering in Pt–Sn nanoalloys supported on CeO2 thin films have been studied by means of synchrotron radiation photoelectron spectroscopy and density functional calculations. Using CO molecules as a probe, we explored the development of the surface structure of supported Pt–Sn nanoalloys with respect to a …
The Pt–Sn/CeO 2 catalyst was also tested in a second reactor setup for propane dehydrogenation at reaction temperatures of 550 and 680 °C to verify the stability and carbon balance, and the results show that in …
Propane dehydrogenation on Pt–Sn/Al 2 O 3 and Pt–Sn/ZnAl 2 O 4 was performed, and the Pt–Sn/ZnAl 2 O 4 catalyst showed a stronger tolerance for catalytic deactivation than the Pt–Sn/Al 2 O 3 catalyst. In this study, we propose that the high catalytic stability of Pt–Sn/ZnAl 2 O 4 originates from the relatively faster coke mobility …
Nhận xét phiên 17/10, dự báo 18/10 sẽ tăng hơn 25₫. Chủ đề trong ' Thị trường chứng khoán ' bởi haihah3, 17/10/2023 . Có 3118 người đang online, trong đó có 401 thành viên. 13:08 (UTC+07:00) Bangkok, Hanoi, Jakarta. Có 0 người đang xem box này (Thành viên: 0, Khách: 0) Trang 1/2. 1 2 Tiếp >.
Long 1133, canh chốt 1165. Chim lợn sai chỉ làm mất cơ hội / Bìm bịp sai có khi mãi mãi ko về bờ. Loan tin | Thích | Báo vi phạm. stocker_healer Thành viên gắn bó với f319. Tham gia ngày: 26/05/2020 Đã được thích: 2.859 #1547. 18/10/2023, 10:57.
Based on the FT-EXAFS spectra in Fig. 7, it was determined that the sample reduced at 400 °C (Pt 1 /ATO) showed Pt–Sn interactions, while both Pt/C and the sample reduced at 100 °C (Pt NP/ATO) only showed Pt–Pt bonds. Furthermore, the Pt–Sn CN was determined to be 2.61 for the sample reduced at 400 °C and no Pt–Pt bonding was …
Remarkably, the Pt 1 Cu 2 /SN-MWCNTs show an obviously larger electroactive surface area and higher mass activity, stability, and CO poisoning resistance in methanol oxidation compared to Pt/SN-MWCNTs, Pt/S-MWCNTs, Pt/N-MWCNTs, and commercial Pt/C. Density functional theory studies confirm that the co-doping of S and N …
The presence of Bu 3 SnH during the synthesis has a significant effect on the Pt NPs crystallization process. The THF solution turned to black instantly when the synthesis was performed at low Sn/Pt molar ratio, and the Pt NPs started to precipitate from THF in 10 min (Fig. S1).When the Sn/Pt ratio was increased to 1, a step-wise color …
An increase in the Sn/Pt ratio will further reduce the particle size of Pt and increase its dispersion. When the Sn/Pt ratio is 1.5, it shows the best catalytic activity. The metal …
Pt and Pt-Sn catalysts supported on SiO{sub 2} and {gamma}-Al{sub 2}O{sub 3} and prepared by impregnation have been studied by temperature-programmed reduction (TPR), hydrogen chemisorption, temperature-programmed desorption (TPD), and catalytic dehydrogenation of propane. Without the promoter Pt shows the same initial specific …
2. ĐẠI HỌC SPKT VINH ĐỒ ÁN ĐỘNG CƠ ĐỐT TRONG SVTH : PHẠM VĂN TUẤN Lớp ĐHOTOK7 Trang 2 PHẦN I :TÍNH TOÁN CHU TRÌNH CÔNG TÁC TRONG ĐỘNG CƠ ĐỐT TRONG I ) Trình tự tính toán : 1.1 )Số liệu ban đầu : Loại đông cơ: 3D6-động cơ Diesel 1hàng, không tăng áp, buồng cháy thống nhất. 1- Công suất của động …
Catalytic propane dehydrogenation is an attractive method to produce propylene while avoiding the issues of its traditional synthesis via naphtha steam cracking of naphtha. In this contribution, a series of Pt-Sn/SBA-16 catalysts were synthesized and evaluated for this purpose. Bimetallic Pt-Sn catalysts were more active than catalysts …
After reduction, the crystallite size for Pt-Sn/kaolinite catalyst was sharply decreased due to possible electron modification of Sn modifying the Pt surface when the …
The effect of the addition of different promoters, such as, Ce, Zn and Co (0.3, 0.5 and 0.7 wt%) to the trimetallic Pt–Sn–K/Al2O3 catalyst in order to enhance performance of propane dehydrogenation was investigated and characterized with several analytic techniques, including, TPR, XRF, UV analysis, SEM and TGA–DTA. The catalysts were …
the industrial Pt–Sn/Al 2O 3 catalyst. In all cases, a combination of Pt with a second metal (In, Sn, Ga, Cu, Zn, etc.) bene cially in uenced the catalyst performance as compared to mono-metallic Pt catalysts.4–9 While the selectivity for most of the systems reaches high levels, all of them suffer from deactiva-tion.
The solid-state growth of the product phases in bulk and electroplated diffusion couples of the Pd–Sn and the Pt–Sn systems is reported at various temperatures, ranging from room temperature to 215 °C. The growth rate of the product phase in the Pt–Sn system is found to be much lower compared to the Pd–Sn system and the Au–Sn …
With the PTT test, the reference range is between 25 and 33 seconds. As with the PT test, a higher PTT number means your blood is taking longer than usual to clot. A lower PTT number means that your blood is clotting faster than normal. There are several reasons why this might occur. Clotting Too Quickly.
Our findings depict an unprecedented evolution process of the active sites of the PtSn/Al 2 O 3, and afford an effectual nanostructure engineering pathway for stable PDH catalysts. …
(Beaches MLS) For Sale: 1165 SE Mendoza Ave #5, Port Saint Lucie, FL 34952 ∙ $136,000 ∙ MLS# RX-10863112 ∙ No trees on this lot ready to start building. Last lot in the area, Oversized lot 83 x 125 in this beaut...
Pt/Sn-containing MFI zeolites prepared by one-pot hydro-thermal methods are highly active and selective catalysts for propane dehydrogenation. An alternative preparation method is reported alongside an in-depth characterization of Pt and Sn before and after reaction. Pt species dispersed on highly-