High Catalytic Activity of Pt/Al2O3 Catalyst in CO Oxidation at Room Temperature—A New Insight into Strong Metal–Support Interactions

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1475
Author(s):  
Ireneusz Kocemba ◽  
Izabela Śmiechowicz ◽  
Marcin Jędrzejczyk ◽  
Jacek Rogowski ◽  
Jacek Michał Rynkowski

The concept of very strong metal–support interactions (VSMSI) was defined in regard to the interactions that influence the catalytic properties of catalysts due to the creation of a new phase as a result of a solid-state chemical reaction between the metal and support. In this context, the high catalytic activity of the 1%Pt/Al2O3 catalyst in the CO oxidation reaction at room temperature was explained. The catalyst samples were reduced at different temperatures ranging from 500 °C to 800 °C and characterized using TPR, O2/H2 titration, CO chemisorption, TPD-CO, FTIR-CO, XRD, and TOF-SIMS methods. Based on the obtained results, it was claimed that with very high temperature reduction (800 °C), nonstoichiometric platinum species [Pt(Cl)Ox] strongly anchored to Al2O3 surface are formed. These species act as the oxygen adsorption sites.

2005 ◽  
Vol 900 ◽  
Author(s):  
Shiho Nagano ◽  
Koji Tajiri ◽  
Yutaka Tai

ABSTRACTThiol-passivated gold nanoparticles were adsorbed on several kinds of support materials such as titania-coated silica aerogels and xerogels etc., and then the thiol was removed by heat treatment. The catalytic activity of the prepared composites for CO oxidation reaction was measured, and the effects of the support on the catalytic activity were investigated. Density of the supports, namely, whether aerogel supports or xerogel ones, hardly affected the catalytic activity. It was found that the catalysts having high catalytic activity could be obtained by this preparation method, even using the xerogels as the support. Calcination of the supports before adsorption of the gold nanoparticles affected the activity. The difference of the catalytic activity was observed between the composites with same gold nanoparticle size, so it was considered that the surface condition of the support materials affects the state of gold nanoparticles in composite.


2018 ◽  
Vol 8 (19) ◽  
pp. 4934-4944 ◽  
Author(s):  
Jinghua Liu ◽  
Tong Ding ◽  
Hao Zhang ◽  
Guangcheng Li ◽  
Jinmeng Cai ◽  
...  

The thermally reduced Pt/TiO2(B) catalysts show high catalytic activity and good water resistance for the catalytic oxidation of CO.


2015 ◽  
Vol 17 (48) ◽  
pp. 32140-32148 ◽  
Author(s):  
Qiaohong Li ◽  
Yongqin Wei ◽  
Rongjian Sa ◽  
Zuju Ma ◽  
Kechen Wu

A new Pd3O9@α-Al2O3 catalyst has been designed which shows superior catalytic activity for CO oxidation.


Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131 ◽  
Author(s):  
Rola Mohammad Al Soubaihi ◽  
Khaled Mohammad Saoud ◽  
Myo Tay Zar Myint ◽  
Mats A. Göthelid ◽  
Joydeep Dutta

Carbon monoxide (CO) oxidation is considered an important reaction in heterogeneous industrial catalysis and has been extensively studied. Pd supported on SiO2 aerogel catalysts exhibit good catalytic activity toward this reaction owing to their CO bond activation capability and thermal stability. Pd/SiO2 catalysts were investigated using carbon monoxide (CO) oxidation as a model reaction. The catalyst becomes active, and the conversion increases after the temperature reaches the ignition temperature (Tig). A normal hysteresis in carbon monoxide (CO) oxidation has been observed, where the catalysts continue to exhibit high catalytic activity (CO conversion remains at 100%) during the extinction even at temperatures lower than Tig. The catalyst was characterized using BET, TEM, XPS, TGA-DSC, and FTIR. In this work, the influence of pretreatment conditions and stability of the active sites on the catalytic activity and hysteresis is presented. The CO oxidation on the Pd/SiO2 catalyst has been attributed to the dissociative adsorption of molecular oxygen and the activation of the C-O bond, followed by diffusion of adsorbates at Tig to form CO2. Whereas, the hysteresis has been explained by the enhanced stability of the active site caused by thermal effects, pretreatment conditions, Pd-SiO2 support interaction, and PdO formation and decomposition.


CrystEngComm ◽  
2021 ◽  
Vol 23 (13) ◽  
pp. 2538-2546
Author(s):  
Min Yang ◽  
Guangshe Li ◽  
Huixia Li ◽  
Junfang Ding ◽  
Yan Wang ◽  
...  

For the first time, the growth behavior with size-dependent Fe occupancies at different sites of MgFe2O4 was examined. Hybrid catalysts of Pt/MgFe2O4 with a support size of 20.6 nm exhibited an optimal performance of CO oxidation.


2011 ◽  
Vol 133 (10) ◽  
pp. 3444-3451 ◽  
Author(s):  
Fan Yang ◽  
Jesús Graciani ◽  
Jaime Evans ◽  
Ping Liu ◽  
Jan Hrbek ◽  
...  

2016 ◽  
Vol 6 (3) ◽  
pp. 869-874 ◽  
Author(s):  
Shu-Tao Gao ◽  
Weihua Liu ◽  
Cheng Feng ◽  
Ning-Zhao Shang ◽  
Chun Wang

Ag–Pd alloys deposited on an amine-functionalized UiO-66(NH2–UiO-66) have been successfully prepared via a pre-coordination method and used as a AgPd@NH2–UiO-66 catalyst with 100% H2 selectivity and a high catalytic activity.


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