A Comparative Study of the Catalytic Performance of Pt-Based Bi and Trimetallic Nanocatalysts Towards Methanol, Ethanol, Ethylene Glycol, and Glycerol Electro-Oxidation

2020 ◽  
Vol 20 (10) ◽  
pp. 6274-6285 ◽  
Author(s):  
Hadla S. Ferreira ◽  
Martin Gocyla ◽  
Hadma S. Ferreira ◽  
Rennan G. O. Araujo ◽  
Caio V. S. Almeida ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fuel Cells ◽  
Ethylene Glycol ◽  
Inductively Coupled Plasma ◽  
Catalytic Performance ◽  
X Ray ◽  
Onset Potential ◽  
Oxidation Of Methanol ◽  
Catalyst Composition ◽  
Electro Oxidation

Carbon-supported platinum is used as an anode and cathode electrocatalyst in low-temperature fuel cells fueled with low-molecular-weight alcohols in fuel cells. The cost of Pt and its low activity towards the complete oxidation of these fuels are significant barriers to the widespread use of these types of fuel cells. Here, we report on the development of PtRhNi nanocatalysts supported on carbon made using a reduction chemistry method with different atomic rates. The catalytic activity of the developed catalysts towards the electro-oxidation of methanol, ethanol, ethylene glycol, and glycerol in acidic media was studied. The obtained catalysts performances were compared with both commercial Pt/C and binary Pt75Ni25/C catalyst. The nanostructures were characterized, employing inductively coupled plasma optical emission spectrometer, X-ray diffraction, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The binary catalyst presents a mean particle size of around 2 nm. Whereas the ternary catalysts present particles of similar size and with some large alloy and core–shell structures. The alcohol oxidation onset potential and the current density measured after 3600 s of chronoamperometry were used to classify the catalytic activity of the catalysts towards the oxidation of methanol, ethanol, ethylene glycol, and glycerol. The best PtRhNi/C catalyst composition (i.e., Pt43Rh43Ni14/C) presented the highest activity for alcohols oxidation compared with all catalysts studied, indicating the proper tuning composition influence in the catalytic activity. The enhanced activity of Pt43Rh43Ni14/C can be attributed to the synergic effect of trimetallic compounds, Pt, Ni, and Rh.

The Impregnating Reduction Method for Synthesis of Pt–Ru Nanoparticles and Its Catalytic Performance for Methanol Electro-oxidation

2015 ◽  
Vol 12 (4) ◽  
Author(s):  
Long-long Wang ◽  
Hong-min Mao ◽  
Xiao-jin Zhou ◽  
Qun-jie Xu ◽  
Qiao-xia Li
Keyword(s):  
Reduction Method ◽  
Average Particle Size ◽  
Catalytic Performance ◽  
Average Particle ◽  
X Ray ◽  
Onset Potential ◽  
Ru Nanoparticles ◽  
Oxidation Of Methanol ◽  
Transmission Electron ◽  
Electro Oxidation

Well-dispersed and low Pt content Pt–Ru/C nanoparticles were prepared by a developed impregnating reduction method with sodium citrate as stabilizer. The as-prepared Pt–Ru/C catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. TEM showed that the Pt–Ru particles were quite uniformly distributed on the surface of the carbon with an average particle size of 3.5–4.5 nm. The effect of pH values on methanol electro-oxidation reaction was examined by cyclic voltammetry (CV) and chronoamperometry (CA). Pre-adsorbed CO monolayer stripping was used to evaluate the antipoisoning ability. The results showed that Pt–Ru/C (pH = 8) catalyst had the highest catalytic activity and stability toward the oxidation of methanol. Finally, comparing Pt–Ru/C (Pt–Ru 20 wt.%, Pt/Ru = 1:1) catalysts with Pt/C (Pt 20 wt.%), the onset potential was 200 mV lower and electrochemical active area was much bigger.

scholarly journals A Polyoxometalate Composite Based on Hierarchical MIL-101 with Enhanced Catalytic Activity in Methanolysis of Styrene Oxide

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 772
Author(s):  
Tian Zhao ◽  
Hexin Zhu ◽  
Ming Dong
Keyword(s):  
Catalytic Activity ◽  
Inductively Coupled Plasma ◽  
Styrene Oxide ◽  
Optical Emission ◽  
Catalytic Performance ◽  
Emission Spectrometry ◽  
Composite Catalyst ◽  
Immersion Method ◽  
X Ray ◽  
Inductively Coupled

A new efficient polyoxometalate composite catalyst of hierarchical MIL-101 and phosphotungstic acid (PTA) was facilely prepared by the immersion method. The material was thoroughly characterized by powder x-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and inductively coupled plasma‒optical emission spectrometry (ICP-OES). Compared to the pristine nonhierarchical MIL-101 composite, the hierarchical composite demonstrated much higher catalytic performance in methanolysis of styrene oxide, such as catalytic activity and reusability.

scholarly journals Bifunctional Tailoring of Platinum Surfaces with Earth Abundant Iron Oxide Nanowires for Boosted Formic Acid Electro-Oxidation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Bilquis Ali Al-Qodami ◽  
Heba H. Farrag ◽  
Sayed Youssef Sayed ◽  
Nageh K. Allam ◽  
Bahgat E. El-Anadouli ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Formic Acid ◽  
Electrochemical Impedance ◽  
Bulk Composition ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Electro Oxidation ◽  
Formic Acid Fuel Cells

To expedite the marketing of direct formic acid fuel cells, a peerless inexpensive binary FeOx/Pt nanocatalyst was proposed for formic acid electro-oxidation (FAO). The roles of both catalytic ingredients (FeOx and Pt) were inspired by testing the catalytic performance of FAO at the FeOx/Au and FeOx/GC analogies. The deposition of FeOx proceeded electrochemically with a post‐activating step that identified the catalyst’s structure and performance. With a proper adaptation for the deposition and activation processes, the FeOx/Pt nanocatalyst succeeded to mitigate the typical CO poisoning that represents the principal element deteriorating the catalytic performance of the direct formic acid fuel cells. It also provided a higher (eightfold) catalytic efficiency than the bare Pt substrates toward FAO with a much better durability. Field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) were all employed to inspect, respectively, the surface morphology, bulk composition, and crystal structure of the catalyst. The electrochemical impedance spectra could correlate the charge transfer resistances for FAO over the inspected set of catalysts to explore the role of FeOx in mediating the reaction mechanism.

scholarly journals The Effect of Mg and Zn Dopants on Pt/Al2O3 for the Dehydrogenation of Perhydrodibenzyltoluene

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 490
Author(s):  
Rudaviro Garidzirai ◽  
Phillimon Modisha ◽  
Innocent Shuro ◽  
Jacobus Visagie ◽  
Pieter van Helden ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Flow Reactor ◽  
Plug Flow ◽  
Optical Emission ◽  
Catalytic Performance ◽  
Emission Spectrometry ◽  
Hydrogen Yield ◽  
X Ray ◽  
Temperature Programmed

The effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst were investigated for dehydrogenation of perhydrodibenzyltoluene (H18-DBT) as a liquid organic hydrogen carrier. Al2O3 supports were modified with Mg and Zn to produce Mg-Al2O3 and Zn-Al2O3 with a target loading of 3.8 wt.% for dopants. The modified supports were impregnated with chloroplatinic acid solution to produce the catalysts Pt/Al2O3, Pt/Mg-Al2O3 and Pt/Zn-Al2O3 of 0.5 wt.% Pt loading. Thereafter, the catalysts were characterised using inductively coupled plasma- optical emission spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, hydrogen temperature-programmed reduction, carbon-monoxide pulse chemisorption, ammonia temperature-programmed desorption, X-ray diffraction and transmission electron microscopy. The dehydrogenation experiments were performed using a horizontal plug flow reactor system and the catalyst time-on-stream was 22 h. Pt/Mg-Al2O3 showed the highest average hydrogen flowrate of 29 nL/h, while an average of 27 nL/h was obtained for both Pt/Al2O3 and Pt/Zn-Al2O3. This has resulted in a hydrogen yield of 80% for Pt/Mg-Al2O3, 71% for Pt/Zn-Al2O3 and 73% for Pt/Al2O3. In addition, the conversion of H18-DBT ranges from 99% to 92%, Pt 97–90% and 96–90% for Pt/Mg-Al2O3, Pt/Zn-Al2O3 and Pt/Al2O3, respectively. Following the latter catalyst order, the selectivity to dibenzyltoluene (H0-DBT) ranges from 78% to 57%, 75–51% and 71–45%. Therefore, Pt/Mg-Al2O3 showed improved catalytic performance towards dehydrogenation of H18-DBT.

Microfluidic Synthesis and Electrochemical Performance of Ternary Metals Nanoalloy: FePtSn

2018 ◽  
Vol 913 ◽  
pp. 831-837
Author(s):  
Ju Gang Ma ◽  
Jun Mei Wang ◽  
Shuai Li ◽  
Yu Jun Song
Keyword(s):  
Electrochemical Performance ◽  
Active Sites ◽  
Annealing Treatment ◽  
Active Surface ◽  
Catalytic Performance ◽  
Synthesis Process ◽  
Methanol Oxidation Reaction ◽  
X Ray ◽  
Onset Potential ◽  
Surface Areas

The ternary FePtSn alloy nanoparticles (NPs) were synthesized via a simple programmed microfluidic process, showing a great electrochemical performance in methanol oxidation reaction (MOR). The synthesis process exhibited convenient and spatial-temporal kinetics control of the NPs formation for a narrow size distribution, ultra-small (~2nm) and good dispersion features. The morphology, crystal structure and composition of FePtSn NPs were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD). FePtSn/C nanocatalyst ink could be further prepared by mixing the as-synthesized or annealed FePtSn NPs with carbon black powder and nafion. Their electrocatalytic performances were tested by the electrochemical work station. By contrast, the annealing treatment made more active sites exposed and facilitated the catalytic performance of FePtSn/C NPs. The electrochemical active surface areas (ECSAs, 42.8m2/g), catalytic activity (If: 588.1 mA/mg-Pt) and electrochemical durability of FePtSn/C nanocatalysts after annealing were greatly improved, comparing with as-synthesized samples and commercial Pt/C nanocatalysts for MOR. In addition, the onset potential of annealed FePtSn/C nanocatalysts was improved, much better than the commercial Pt/C nanocatalysts.

scholarly journals Generalized Methodology for Inserting Metal Heteroatoms into the Layered Zeolite Precursor RUB-36 by Interlayer Expansion

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 530 ◽  
Author(s):  
Chaoqun Bian ◽  
Xiao Wang ◽  
Lan Yu ◽  
Fen Zhang ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Zeolite Sample ◽  
X Ray ◽  
Inductively Coupled ◽  
Temperature Programmed ◽  
First Time ◽  
N2 Sorption

The incorporation of metal heteroatoms into zeolites is an effective modification strategy for enhancing their catalytic performance. Herein, for the first time we report a generalized methodology for inserting metal heteroatoms (such as Sn, Fe, Zn, and Co) into the layered zeolite precursor RUB-36 via interlayer expansion by using the corresponding metal acetylacetate salt. Through this generalized methodology, Sn-JHP-1, Fe-JHP-1, Zn-JHP-1 and Co-JHP-1 zeolites could be successfully prepared by the reaction of RUB-36 and corresponding metal acetylacetate salt at 180 °C for 24 h in the presence of HCl solution. As a typical example, Sn-JHP-1 and calcined Sn-JHP-1 (Sn-JHP-2) zeolite is well characterized by the X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (UV-Vis), inductively coupled plasma (ICP), N2 sorption, temperature-programmed-desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS) techniques, which confirm the expansion of adjacent interlayers and thus the incorporation of isolated Sn sites within the zeolite structure. Notably, the obtained Sn-JHP-2 zeolite sample shows enhanced catalytic performance in the conversion of glucose to levulinic acid (LA) reaction.

scholarly journals Catalytic Activity of Polynuclear vs. Dinuclear Aroylhydrazone Cu(II) Complexes in Microwave-Assisted Oxidation of Neat Aliphatic and Aromatic Hydrocarbons

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 47 ◽  
Author(s):  
Manas Sutradhar ◽  
Tannistha Barman ◽  
Armando Pombeiro ◽  
Luísa Martins
Keyword(s):  
Catalytic Activity ◽  
Aromatic Hydrocarbons ◽  
Catalytic Performance ◽  
Antiproliferative Agents ◽  
One Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mild Conditions ◽  
Microwave Assisted ◽  
Aliphatic And Aromatic Hydrocarbons

One-dimensional (1D) polynuclear Cu(II) complex (1) derived from (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H2L) is synthesized and characterized by elemental analysis, IR spectroscopy, ESI-MS, and single crystal X-ray crystallography. Its catalytic performance towards the solvent-free microwave-assisted peroxidative oxidation of aliphatic and aromatic hydrocarbons under mild conditions is compared with that of dinuclear Cu(II) complexes (2 and 3) of the same ligand, previously reported as antiproliferative agents. Polymer 1 exhibits the highest activity, either for the oxidation of cyclohexane (leading to overall yields, based on the alkane, of up to 39% of cyclohexanol and cyclohexanone) or towards the oxidation of toluene (selectively affording benzaldehyde up to a 44% yield), after 2 or 2.5 h of irradiation at 80 or 50 °C, respectively.

scholarly journals Preparation, characterization and catalytic performance of Pt supported on porous carbonaceous materials in the oxidation of toluene as a volatile organic compound

2019 ◽  
Vol 45 ◽  
pp. 146867831988793
Author(s):  
Niloofar Atashi ◽  
Mohammad Hasan Peyrovi ◽  
Nastaran Parsafard
Keyword(s):  
Carbon Nanotube ◽  
Organic Compound ◽  
Power Law ◽  
Volatile Organic Compound ◽  
Inductively Coupled Plasma ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
X Ray ◽  
Volatile Organic

Platinum-carbonaceous catalysts were prepared by the wet impregnation method and tested for catalytic oxidation of toluene as a volatile organic compound. The textural properties of the constructed catalysts were considered by X-ray diffraction, X-ray fluorescence, inductively coupled plasma – optical emission spectroscopy, Fourier transform infrared, scanning electron microscope and N2 adsorption–desorption analysis. The catalytic assessments showed that the best activity (>99%) and high stability and selectivity to CO2 (>99%) are related to platinum-supported carbon nanotube. The curves of the conversion and selectivity demonstrate that the performance of catalysts to eliminate the volatile organic compound and turn it into CO2 conforms to the following descending order: platinum-supported carbon nanotube >platinum-supported graphene >platinum-supported activated carbon >platinum-supported carbon nanofibre. The kinetic of toluene oxidation has been evaluated as a function of toluene and oxygen partial pressures in different temperatures. Two kinetic models (Power Law and Mars–van Krevelen mechanisms) were applied to the reaction and compared with the experimental data. Mars–van Krevelen model is more appropriate than the Power Law model for this reaction as Mars–van Krevelen model showed better prediction of the behaviour of the reaction.

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