scholarly journals Glucose–Carbon Hybrids as Pt Catalyst Supports for the Continuous Furfural Hydroconversion in Gas Phase

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Sergio Morales-Torres ◽  
Luisa M. Pastrana-Martínez ◽  
Juan A. Pérez-García ◽  
Francisco J. Maldonado-Hódar
Keyword(s):  
Gas Phase ◽  
Catalyst Deactivation ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Operating Conditions ◽  
Pt Catalyst ◽  
Main Reaction ◽  
Surface Areas ◽  
Glucose Carbon ◽  
Reduced Graphene

Glucose–carbon hybrids were synthetized with different carbon materials, namely carbon nanotubes, reduced graphene oxide, carbon black and activated carbon by a hydrothermal treatment. These carbon hybrids were used as Pt-supports (1 wt.%) for the furfural (FUR) hydroconversion in the gas phase at mild operating conditions (i.e., P = 1 atm and T = 200 °C). The physicochemical properties (porosity, surface chemistry, Pt-dispersion, etc.) were analyzed by different techniques. Glucose–carbon hybrids presented apparent surface areas between 470–500 m2 g−1, a neutral character and a good distribution of small Pt-nanoparticles, some large ones with octahedral geometry being also formed. Catalytic results showed two main reaction pathways: (i) FUR hydrogenation to furfuryl alcohol (FOL), and (ii) decarbonylation to furane (FU). The products distribution depended on the reaction temperature, FOL or FU being mainly produced at low (120–140 °C) or high temperatures (170–200 °C), respectively. At intermediate temperatures, tetrahydrofurfuryl alcohol was formed by secondary FOL hydrogenation. FUR hydroconversion is a structure-sensitive reaction, rounded-shape Pt-nanoparticles producing FU, while large octahedral Pt-particles favor the formation of FOL. Pt-catalysts supported on glucose–carbon hybrids presented a better catalytic performance at low temperature than the catalyst prepared on reference material, no catalyst deactivation being identified after several hours on stream.

scholarly journals Tuning the Reaction Selectivity over MgAl Spinel-Supported Pt Catalyst in Furfuryl Alcohol Conversion to Pentanediols

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 415
Author(s):  
Xinsheng Li ◽  
Jifeng Pang ◽  
Jingcai Zhang ◽  
Xianquan Li ◽  
Yu Jiang ◽  
...  
Keyword(s):  
Furfuryl Alcohol ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Major Product ◽  
Pt Catalyst ◽  
Reaction Products ◽  
Strong Base ◽  
Reaction Selectivity ◽  
Supported Pt Catalysts ◽  
Alcohol Conversion

Catalytic conversion of biomass-derived feedstock to high-value chemicals is of remarkable significance for alleviating dependence on fossil energy resources. MgAl spinel-supported Pt catalysts were prepared and used in furfuryl alcohol conversion. The approaches to tune the reaction selectivity toward pentanediols (PeDs) were investigated and the catalytic performance was correlated to the catalysts’ physicochemical properties based on comprehensive characterizations. It was found that 1–8 wt% Pt was highly dispersed on the MgAl2O4 support as nanoparticles with small sizes of 1–3 nm. The reaction selectivity did not show dependence on the size of Pt nanoparticles. Introducing LiOH onto the support effectively steered the reaction products toward the PeDs at the expense of tetrahydrofurfuryl alcohol (THFA) selectivity. Meanwhile, the major product in PeDs was shifted from 1,5-PeD to 1,2-PeD. The reasons for the PeDs selectivity enhancement were attributed to the generation of a large number of medium-strong base sites on the Li-modified Pt catalyst. The reaction temperature is another effective factor to tune the reaction selectivity. At 230 °C, PeDs selectivity was enhanced to 77.4% with a 1,2-PeD to 1,5-PeD ratio of 3.7 over 4Pt/10Li/MgAl2O4. The Pt/Li/MgAl2O4 catalyst was robust to be reused five times without deactivation.

scholarly journals Catalytic Dehydrogenation of Methylcyclohexane by Pt Nanoparticles Supported on Nitrogen doped Carbon

2020 ◽  
Vol 194 ◽  
pp. 01030
Author(s):  
Jian Wang ◽  
Shiguang Fan ◽  
Xuan Xu ◽  
Huiru Yun ◽  
He Liu ◽  
...  
Keyword(s):  
Surface Area ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Support Surface ◽  
Catalytic Dehydrogenation ◽  
Nitrogen Doped ◽  
Surface Areas ◽  
Transmission Electron ◽  
Methylcyclohexane Dehydrogenation ◽  
Nitrogen Doped Carbon

Pt nanoparticles supported on nitrogen doped carbon (Pt/CN) catalysts with different surface areas were obtained and characterized by transmission electron microscope （TEM） and brunner-emmet-teller （BET）. The characterized results showed that Pt nanoparticles dispersed uniformly on the support surface, and the surface area of the Pt/CN catalyst increased with the increase of annealing temperature. Subsequently, the catalytic performance of Pt/CN catalysts for methylcyclohexane dehydrogenation was studied. The activity of Pt/CN catalysts in methylcyclohexane dehydrogenation increased with the increase of the surface area, Pt/CN-1000 catalyst has the largest surface area and the highest catalytic activity, with the methylcyclohexane conversion of 99% and the TOF value of 424.78 h-1 at 180 ℃ for 150 minutes.

scholarly journals Understanding Hydrodechlorination of Chloromethanes. Past and Future of the Technology

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1462
Author(s):  
Sichen Liu ◽  
Javier A. Otero ◽  
Maria Martin-Martinez ◽  
Daniel Rodriguez-Franco ◽  
Juan J. Rodriguez ◽  
...  
Keyword(s):  
Catalyst Deactivation ◽  
Global Analysis ◽  
Catalytic Performance ◽  
Operating Conditions ◽  
Light Olefins ◽  
Synthesis Methods ◽  
Chlorinated Pollutants ◽  
New Perspective ◽  
Kinetics Of ◽  
Experimental And Theoretical Studies

Chloromethanes are a group of volatile organic compounds that are harmful to the environment and human health. Abundant studies have verified that hydrodechlorination might be an effective treatment to remove these chlorinated pollutants. The most outstanding advantages of this technique are the moderate operating conditions used and the possibility of obtaining less hazardous valuable products. This review presents a global analysis of experimental and theoretical studies regarding the hydrodechlorination of chloromethanes. The catalysts used and their synthesis methods are summarized. Their physicochemical properties are analyzed in order to deeply understand their influence on the catalytic performance. Moreover, the main causes of the catalyst deactivation are explained, and prevention and regeneration methods are suggested. The reaction systems used and the effect of the operating conditions on the catalytic activity are also analyzed. Besides, the mechanisms and kinetics of the process at the atomic level are reviewed. Finally, a new perspective for the upgrading of chloromethanes, via hydrodechlorination, to valuable hydrocarbons for industry, such as light olefins, is discussed.

scholarly journals Catalytic Steam Reforming of Toluene: Understanding the Influence of the Main Reaction Parameters over a Reference Catalyst

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 813 ◽  
Author(s):  
Hua Lun Zhu ◽  
Laura Pastor-Pérez ◽  
Marcos Millan
Keyword(s):  
Steam Reforming ◽  
High Performance ◽  
Space Velocity ◽  
Catalytic Performance ◽  
H2 Production ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Main Reaction ◽  
Toluene Conversion ◽  
Steam Reforming Of Toluene

Identifying the suitable reaction conditions is key to achieve high performance and economic efficiency in any catalytic process. In this study, the catalytic performance of a Ni/Al2O3 catalyst, a benchmark system—was investigated in steam reforming of toluene as a biomass gasification tar model compound to explore the effect of reforming temperature, steam to carbon (S/C) ratio and residence time on toluene conversion and gas products. An S/C molar ratio range from one to three and temperature range from 700 to 900 °C was selected according to thermodynamic equilibrium calculations, and gas hourly space velocity (GHSV) was varied from 30,600 to 122,400 h−1 based on previous work. The results suggest that 800 °C, GHSV 61,200 h−1 and S/C ratio 3 provide favourable operating conditions for steam reforming of toluene in order to get high toluene conversion and hydrogen productivity, achieving a toluene to gas conversion of 94% and H2 production of 13 mol/mol toluene.

Catalytic performance of Pt nanoparticles on reduced graphene oxide for methanol electro-oxidation

Carbon ◽  
2010 ◽  
Vol 48 (4) ◽  
pp. 1124-1130 ◽  
Author(s):  
Yongjie Li ◽  
Wei Gao ◽  
Lijie Ci ◽  
Chunming Wang ◽  
Pulickel M. Ajayan
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Reduced Graphene ◽  
Electro Oxidation

scholarly journals Small Reduced Graphene Oxides for Highly Efficient Oxygen Reduction Catalysts

2021 ◽  
Vol 22 (22) ◽  
pp. 12300
Author(s):  
Su-Jeong Bak ◽  
Sun-I Kim ◽  
Su-yeong Lim ◽  
Taehyo Kim ◽  
Se-Hun Kwon ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Pt Nanoparticles ◽  
Graphene Oxides ◽  
Highly Efficient ◽  
Surface Areas ◽  
Reduced Graphene ◽  
High Metal ◽  
Oxygen Reduction Catalysts ◽  
Reduced Graphene Oxides ◽  
Reduction Catalysts

We demonstrated highly efficient oxygen reduction catalysts composed of uniform Pt nanoparticles on small, reduced graphene oxides (srGO). The reduced graphene oxide (rGO) size was controlled by applying ultrasonication, and the resultant srGO enabled the morphological control of the Pt nanoparticles. The prepared catalysts provided efficient surface reactions and exhibited large surface areas and high metal dispersions. The resulting Pt/srGO samples exhibited excellent oxygen reduction performance and high stability over 1000 cycles of accelerated durability tests, especially the sample treated with 2 h of sonication. Detailed investigations of the structural and electrochemical properties of the resulting catalysts suggested that both the chemical functionality and electrical conductivity of these samples greatly influence their enhanced oxygen reduction efficiency.

Highly Sensitive Electrochemical Aptasensor for Detection of Glypican-3 Using Hemin-Reduced Graphene Oxide-Platinum Nanoparticles Coupled with Conductive Reduced Graphene Oxide-Gold Nanoparticles

2021 ◽  
Vol 17 (12) ◽  
pp. 2444-2454
Author(s):  
Guiyin Li ◽  
HaiMei Li ◽  
Wei Chen ◽  
Huijiang Chen ◽  
Guanxiong Wu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Low Cost ◽  
Pt Nanoparticles ◽  
Great Promise ◽  
Electrochemical Aptasensor ◽  
Surface Areas ◽  
Reduced Graphene ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

An electrochemical aptasensor for quantitatively detecting glypican-3 (GPC3) was constructed by combining hemin-reduced graphene oxide-platinum (H-rGO-Pt) nanoparticles (NPs) with reduced graphene oxide-gold (rGO-Au) nanoparticles (NPs). Herein, the rGO-Au NPs deposited onto screen-printed electrodes resulted in signal amplification due to their large surface areas. Meanwhile, highly conductive H-rGO-Pt NPs acted as a sensing medium that improved electrical conductivity and as an indicator for monitoring peak current for determination. A GPC3 aptamer (GPC3apt) with a low equilibrium dissociation constant was used as a bio-recognition molecule. GPC3apt specifically captured GPC3 proteins and formed aptamer-GPC3 complexes, which impeded electron transfer and thus hampered the redox signal of hemin in H-rGO-Pt NPs. This developed electrochemical aptasensor showed a linear response to GPC3 (from 0.001 μg/mL to 10 μg/mL) and had a detection limit of 0.001 μg/mL. This work provides a low-cost and highly sensitive detection with and good recovery for GPC3 and holds great promise for the clinical diagnosis of hepatocellular carcinoma.

scholarly journals Effect of Operating Conditions on the Performance of Rh/TiO2 Catalyst for the Reaction of LPG Steam Reforming

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 374
Author(s):  
Aliki Kokka ◽  
Theodora Ramantani ◽  
Paraskevi Panagiotopoulou
Keyword(s):  
Reaction Temperature ◽  
Steam Reforming ◽  
Catalyst Deactivation ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Operating Conditions ◽  
Propane Conversion ◽  
Liquefied Petroleum Gas ◽  
Steam Content ◽  
Tio2 Catalyst

The catalytic performance of Rh/TiO2 catalyst was investigated for the reaction of Liquefied Petroleum Gas (LPG) steam reforming with respect to the operating conditions employed. The impacts of reaction temperature, steam/C ratio, Gas Hourly Space Velocity (GHSV), and time were examined and discussed both in the absence and presence of butane in the feed. It was found that the catalytic performance is improved by increasing the reaction temperature, steam content in the feed, and/or by decreasing GHSV. In the presence of butane in the feed, the effect of H2O/C ratio on catalytic performance is prominent, whereas the opposite was observed for the effect of GHSV. The propane conversion curve decreases by adding butane in the feed, indicating that the presence of butane retards propane steam reforming. The investigation of the dynamic response of Rh/TiO2 catalyst to variations of H2O/C ratio showed that neither catalytic activity nor product selectivity is varied with time following abrupt changes of the steam/C ratio between 2 and 7. The catalyst exhibited excellent stability with time-on-stream at 500 and 650 °C. However, a reversible catalyst deactivation seems to be operable when the reaction occurs at 600 °C, resulting in a progressive decrease of propane conversion, which, however, can be completely restored by increasing the temperature to 650 °C in He flow, respectively. The long-term stability of Rh/TiO2 catalyst in the form of pellets showed that this catalyst is not only active and selective but also stable, and therefore, it is a promising catalyst for the reaction of LPG steam reforming.

scholarly journals High-throughput computational-experimental screening protocol for the discovery of bimetallic catalysts

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Byung Chul Yeo ◽  
Hyunji Nam ◽  
Hyobin Nam ◽  
Min-Cheol Kim ◽  
Hong Woo Lee ◽  
...  
Keyword(s):  
High Throughput ◽  
Bimetallic Catalysts ◽  
High Throughput Screening ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Platinum Group Metals ◽  
Pt Catalyst ◽  
Electronic Density ◽  
Bimetallic Alloy ◽  
Screening Protocol

AbstractTo accelerate the discovery of materials through computations and experiments, a well-established protocol closely bridging these methods is required. We introduce a high-throughput screening protocol for the discovery of bimetallic catalysts that replace palladium (Pd), where the similarities in the electronic density of states patterns were employed as a screening descriptor. Using first-principles calculations, we screened 4350 bimetallic alloy structures and proposed eight candidates expected to have catalytic performance comparable to that of Pd. Our experiments demonstrate that four bimetallic catalysts indeed exhibit catalytic properties comparable to those of Pd. Moreover, we discover a bimetallic (Ni-Pt) catalyst that has not yet been reported for H2O2 direct synthesis. In particular, Ni61Pt39 outperforms the prototypical Pd catalyst for the chemical reaction and exhibits a 9.5-fold enhancement in cost-normalized productivity. This protocol provides an opportunity for the catalyst discovery for the replacement or reduction in the use of the platinum-group metals.

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