scholarly journals Cellulose nanocrystals (CNCs) as hard templates for preparing mesoporous zeolite Y assemblies with high catalytic activity

2020 ◽  
Vol 22 (15) ◽  
pp. 5115-5122 ◽  
Author(s):  
Samer Abdulridha ◽  
Jiuxing Jiang ◽  
Shaojun Xu ◽  
Zhaoxia Zhou ◽  
He Liang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cellulose Nanocrystals ◽  
Zeolite Y ◽  
Synthesis Method ◽  
High Catalytic Activity ◽  
Mesoporous Zeolite ◽  
Y Zeolite ◽  
Directed Synthesis

Faujasite (FAU) Y zeolite assemblies with high mesoporosity (Sext = 347 m2 g−1 and Vmeso = 0.52 cm3 g−1) were synthesised using sustainable and economic cellulose nanocrystals (CNCs) via a template-directed synthesis method.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

scholarly journals Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane

2018 ◽  
Vol 9 ◽  
pp. 1162-1183 ◽  
Author(s):  
Nor Fazila Khairudin ◽  
Mohd Farid Fahmi Sukri ◽  
Mehrnoush Khavarian ◽  
Abdul Rahman Mohamed
Keyword(s):  
Catalytic Activity ◽  
Catalyst Deactivation ◽  
Synthesis Method ◽  
Gas Production ◽  
Dry Reforming ◽  
Operating Conditions ◽  
Dry Reforming Of Methane ◽  
High Catalytic Activity ◽  
Metal Dispersion ◽  
Recent Developments

Dry reforming of methane (DRM) is one of the more promising methods for syngas (synthetic gas) production and co-utilization of methane and carbon dioxide, which are the main greenhouse gases. Magnesium is commonly applied in a Ni-based catalyst in DRM to improve catalyst performance and inhibit carbon deposition. The aim of this review is to gain better insight into recent developments on the use of Mg as a support or promoter for DRM catalysts. Its high basicity and high thermal stability make Mg suitable for introduction into the highly endothermic reaction of DRM. The introduction of Mg as a support or promoter for Ni-based catalysts allows for good metal dispersion on the catalyst surface, which consequently facilitates high catalytic activity and low catalyst deactivation. The mechanism of DRM and carbon formation and reduction are reviewed. This work further explores how different constraints, such as the synthesis method, metal loading, pretreatment, and operating conditions, influence the dry reforming reactions and product yields. In this review, different strategies for enhancing catalytic activity and the effect of metal dispersion on Mg-containing oxide catalysts are highlighted.

Zeolite Y nanosheet assembled palladium catalysts with high catalytic activity and selectivity in the vinylation of thiophenes

2016 ◽  
Vol 52 (15) ◽  
pp. 3115-3118 ◽  
Author(s):  
Wenqian Fu ◽  
Yu Feng ◽  
Zhongxue Fang ◽  
Qun Chen ◽  
Ting Tang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Activity ◽  
Palladium Catalysts ◽  
Zeolite Y ◽  
High Catalytic Activity ◽  
Pd Catalyst ◽  
Macroporous Structure

Zeolite Y nanosheets with a micro–meso–macroporous structure were synthesized, and applied in the assembly of a Pd catalyst (Pd/NS-Y) for direct vinylation of thiophenes with high activity and selectivity, as compared to Pd(OAc)2, Pd(NO3)2, and Pd(PPh3)4 catalysts.

EXAFS studies on the origin of high catalytic activity in nickel Y zeolite

1987 ◽  
Vol 109 (1) ◽  
pp. 52-55 ◽  
Author(s):  
Mitsuru Sano ◽  
Tetsuya Maruo ◽  
Hideo Yamatera ◽  
Minoru Suzuki ◽  
Yasukazu Saito
Keyword(s):  
Catalytic Activity ◽  
High Catalytic Activity ◽  
Y Zeolite

Framework-confined Sn in Si-beta stabilizing ultra-small Pt nanoclusters as direct propane dehydrogenation catalysts with high selectivity and stability

2019 ◽  
Vol 9 (24) ◽  
pp. 6993-7002 ◽  
Author(s):  
Yansu Wang ◽  
Zhong-Pan Hu ◽  
Wenwen Tian ◽  
Lijiao Gao ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Selectivity ◽  
Synthesis Method ◽  
Propane Dehydrogenation ◽  
High Catalytic Activity ◽  
Pt Nanoclusters ◽  
Post Synthesis ◽  
Excellent Stability

Highly stable Pt/Sn-Si-beta catalysts were prepared via an improved post-synthesis method, exhibiting high catalytic activity, good selectivity and excellent stability for propane dehydrogenation to propene.

Activity and regenerability of dealuminated zeolite Y in liquid phase alkylation of benzene with 1-alkene

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Michal Horňáček ◽  
Pavol Hudec ◽  
Andrej Nociar ◽  
Agáta Smiešková ◽  
Tibor Jakubík
Keyword(s):  
Catalytic Activity ◽  
Liquid Phase ◽  
Hydrochloric Acid ◽  
Zeolite Y ◽  
Batch Reactor ◽  
Selective Extraction ◽  
Y Zeolite ◽  
Hy Zeolite ◽  
Alkylation Of Benzene

AbstractHY-zeolite and its deep-bed dealuminated and EFAL-extracted forms were tested in liquid phase alkylation of benzene with 1-hexadecene in a batch reactor at 120°C. Deep-bed dealumination of the HY-sample at 560 °C followed by careful selective extraction of extra-framework aluminium by hydrochloric acid increased the catalytic activity as well as oxidative regenerability of Y-zeolite.

Interfacial reaction-directed synthesis of a ceria nanotube-embedded ultra-small Pt nanoparticle catalyst with high catalytic activity and thermal stability

2016 ◽  
Vol 4 (37) ◽  
pp. 14148-14154 ◽  
Author(s):  
Yong Wang ◽  
Guolong Song ◽  
Zhenhe Xu ◽  
Federico Rosei ◽  
Dongling Ma ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Interfacial Reaction ◽  
High Catalytic Activity ◽  
Pt Nanoparticle ◽  
Directed Synthesis ◽  
Nanoparticle Catalyst

Due to the ultra-small size of Pt NPs and the extensive contact between Pt and ceria, the ceria nanotube-embedded ultra-small Pt nanoparticle catalyst exhibits remarkable catalytic activity and thermal stability toward CO oxidation.

Facile in situ redox synthesis of Au@Fe2O3 nanocomposites with multifunctional catalytic activity

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhuo Chen ◽  
Xiao-jun Wei ◽  
Jun Liu ◽  
Xiao-meng Lv
Keyword(s):  
Catalytic Activity ◽  
Benzyl Alcohol ◽  
Hybrid Composites ◽  
Synthesis Method ◽  
Catalytic Performance ◽  
High Catalytic Activity ◽  
Oxidation Of Benzyl Alcohol ◽  
Nitrophenol Reduction ◽  
Dispersed Gold

AbstractUsing freshly synthesized Fe(OH)2 matrix and HAuCl4 as precursor, l-lysine as stabilizer and linker, Au nanoparticles coated onto γ-Fe2O3 substrate were in-situ synthesized at room temperature. The Au@Fe2O3 hybrid composites with small highly dispersed gold particles (∼3 nm) exhibited high catalytic activity towards 4-nitrophenol reduction and the oxidation of benzyl alcohol. The results indicated the rate constant for 4-nitrophenol reduction was 5.3 × 10−2 s−1, and displayed efficient catalytic performance in terms of turnover number (TOF) of 134.8 h−1 for the oxidation of benzyl alcohol at 90 ± 1 °C. Furthermore, the facial electrode potential-driven in situ synthesis method paved the way of other metal nanoparticles over Fe2O3.

scholarly journals Pt/Fe co-loaded mesoporous zeolite beta for CO oxidation with high catalytic activity and water resistance

RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 28089-28094 ◽  
Author(s):  
Qinru Li ◽  
Xiaoxia Zhou ◽  
Wanpeng Zhao ◽  
Chunlei Peng ◽  
Huixia Wu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ion Exchange ◽  
Ethylene Glycol ◽  
Co Oxidation ◽  
Water Resistance ◽  
Reduction Method ◽  
Zeolite Beta ◽  
High Catalytic Activity ◽  
Mesoporous Zeolite ◽  
Highly Dispersed

A series of Pt/Fe co-loaded mBeta catalysts with highly dispersed Pt species have been successfully prepared by an ion exchange and subsequent ethylene glycol reduction method, and show excellent catalytic activity and durability in CO oxidation.

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