Titanate Nanotube-Supported Au–Rh Bimetallic Catalysts: Characterization and Their Catalytic Performances in Hydroformylation of Vinyl Acetate

A series of titanate nanotube-supported metal catalysts (M/TNTs, M = Rh, Au orAu–Rh) were facilely synthesized. The effects of different Au contents, reduction processes and sequence of loading metals on their catalytic performances in the hydroformylation of vinyl acetate were comparatively investigated. The results showed that some Au and Rh formed bimetallic particles. Furthermore, the presence of Au in catalysts could significantly improve the selectivity of reaction for aldehydes. Compared with the monometallic catalysts (Rh0.33/TNTs-1 and Au0.49/TNTs-2), the resultant bimetallic catalysts exhibited significantly higher selectivity for aldehydes as well as higher TOF values in the hydroformylation of vinyl acetate. Among them, Au0.52/Rh0.32/TNTs-12 displayed the best catalytic performance. The corresponding selectivity for aldehydes was as high as 88.67%and the turnover frequency (TOF) reached up to 3500 h−1. In addition, for the reduction of Rh3+ and Au3+ ions, the photo-reduction and ethanol-reduction were the optimal techniques under the present conditions, respectively.

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

npj Computational Materials ◽

10.1038/s41524-021-00605-6 ◽

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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Monodispersed palladium–cobalt alloy nanoparticles assembled on poly(N-vinyl-pyrrolidone) (PVP) as a highly effective catalyst for dimethylamine borane (DMAB) dehydrocoupling

RSC Advances ◽

10.1039/c6ra00536e ◽

2016 ◽

Vol 6 (29) ◽

pp. 24097-24102 ◽

Cited By ~ 74

Author(s):

Betül Çelik ◽

Yunus Yıldız ◽

Hakan Sert ◽

Esma Erken ◽

Yagmur Koşkun ◽

...

Keyword(s):

Catalytic Activity ◽

Catalytic Performance ◽

Vinyl Pyrrolidone ◽

Alloy Nanoparticles ◽

Turnover Frequency ◽

Cobalt Alloy ◽

High Turnover ◽

Effective Catalyst ◽

Dimethylamine Borane ◽

Very High

Monodispersed PdCo@PVP NPs showed record catalytic activity, giving the best catalytic performance yet with a very high turnover frequency.

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Effects of Synthesis Parameters on Crystallization Behavior of K-MER Zeolite and Its Morphological Properties on Catalytic Cyanoethylation Reaction

Crystals ◽

10.3390/cryst10020064 ◽

2020 ◽

Vol 10 (2) ◽

pp. 64 ◽

Cited By ~ 3

Author(s):

Ying-Wai Cheong ◽

Ka-Lun Wong ◽

Boon Seng Ooi ◽

Tau Chuan Ling ◽

Fitri Khoerunnisa ◽

...

Keyword(s):

Crystallization Behavior ◽

Catalytic Performance ◽

Morphological Properties ◽

Crystallization Time ◽

Microporous Material ◽

Profound Impact ◽

Synthesis Parameters ◽

Type Zeolite ◽

Catalytic Performances ◽

Zeolite Crystals

MER-type zeolite is an interesting microporous material that has been widely used in catalysis and separation. By carefully controlling the synthesis parameters, a procedure to synthesize K-MER zeolite crystals with various morphologies has been developed. The silica, water and mineralizer content in the synthesis gel, as well as crystallization time and temperature, have a profound impact on the crystallization kinetics, resulting in zeolite solids with various degrees of crystallinity, crystal sizes and shapes. K-MER zeolite crystals with nanorod, bullet-like, prismatic and wheatsheaf-like morphologies have been successfully obtained. The catalytic performances of the K-MER zeolites in cyanoethylation of methanol, under novel non-microwave instant heating, have been investigated. The zeolite in nanosize form shows the best catalytic performance (94.1% conversion, 100% selectivity) while the bullet-like zeolite gives poorest catalytic performance (44.2% conversion, 100% selectivity).

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Preparation and Characterization of Rh/MgSNTs Catalyst for Hydroformylation of Vinyl Acetate: The Rh0 was Obtained by Calcination

Catalysts ◽

10.3390/catal9030215 ◽

2019 ◽

Vol 9 (3) ◽

pp. 215 ◽

Cited By ~ 3

Author(s):

Penghe Su ◽

Ya Chen ◽

Xiaotong Liu ◽

Hongyuan Chuai ◽

Hongchi Liu ◽

...

Keyword(s):

Vinyl Acetate ◽

Atomic Emission ◽

Catalytic Performance ◽

Bet Surface Area ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Atomic Emission Spectrometer ◽

Calcination Method

A simple and practical Rh-catalyzed hydroformylation of vinyl acetate has been synthesized via impregnation-calcination method using silicate nanotubes (MgSNTs) as the supporter. The Rh0 (zero valent state of rhodium) was obtained by calcination. The influence of calcination temperature on catalytic performance of the catalysts was investigated in detail. The catalysts were characterized in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), atomic emission spectrometer (ICP), and Brunauer–Emmett–Teller (BET) surface-area analyzers. The Rh/MgSNTs(a2) catalyst shows excellent catalytic activity, selectivity and superior cyclicity. The catalyst could be easily recovered by phase separation and was used up to four times.

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Improved catalytic effect and metal nanoparticle stability using graphene oxide surface coating and reduced graphene oxide for hydrogen generation from ammonia–borane dehydrogenation

Materials Advances ◽

10.1039/d0ma00441c ◽

2020 ◽

Vol 1 (6) ◽

pp. 1952-1962

Author(s):

Samikannu Prabu ◽

Kung-Yuh Chiang

Keyword(s):

Graphene Oxide ◽

Catalytic Effect ◽

Hydrogen Generation ◽

Catalytic Performance ◽

Metal Nanoparticle ◽

Oxide Surface ◽

Turnover Frequency ◽

High Turnover ◽

Nanoparticle Stability ◽

Reduced Graphene

GO and rGO supported metal NPs exhibited excellent catalytic performance for AB hydrolysis. It also provided a high turnover frequency (TOF) at 25 °C.

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Material Discovery and High Throughput Exploration of Ru Based Catalysts for Low Temperature Ammonia Decomposition

Materials ◽

10.3390/ma13081869 ◽

2020 ◽

Vol 13 (8) ◽

pp. 1869 ◽

Cited By ~ 2

Author(s):

Katherine McCullough ◽

Pei-Hua Chiang ◽

Juan D. Jimenez ◽

Jochen A. Lauterbach

Keyword(s):

Low Temperature ◽

High Throughput ◽

Bimetallic Catalysts ◽

Active Sites ◽

Operating Conditions ◽

Ammonia Decomposition ◽

Turnover Frequency ◽

Surface Sites ◽

Equivalent Number ◽

Apparent Activation Energies

High throughput experimentation has the capability to generate massive, multidimensional datasets, allowing for the discovery of novel catalytic materials. Here, we show the synthesis and catalytic screening of over 100 unique Ru-Metal-K based bimetallic catalysts for low temperature ammonia decomposition, with a Ru loading between 1–3 wt% Ru and a fixed K loading of 12 wt% K, supported on γ-Al2O3. Bimetallic catalysts containing Sc, Sr, Hf, Y, Mg, Zr, Ta, or Ca in addition to Ru were found to have excellent ammonia decomposition activity when compared to state-of-the-art catalysts in literature. Furthermore, the Ru content could be reduced to 1 wt% Ru, a factor of four decrease, with the addition of Sr, Y, Zr, or Hf, where these secondary metals have not been previously explored for ammonia decomposition. The bimetallic interactions between Ru and the secondary metal, specifically RuSrK and RuFeK, were investigated in detail to elucidate the reaction kinetics and surface properties of both high and low performing catalysts. The RuSrK catalyst had a turnover frequency of 1.78 s−1, while RuFeK had a turnover frequency of only 0.28 s−1 under identical operating conditions. Based on their apparent activation energies and number of surface sites, the RuSrK had a factor of two lower activation energy than the RuFeK, while also possessing an equivalent number of surface sites, which suggests that the Sr promotes ammonia decomposition in the presence of Ru by modifying the active sites of Ru.

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Catalytic Oxidation of Formaldehyde Over Mesoporous MnOx-CeO2 Catalysts

International Journal of Nanoscience ◽

10.1142/s0219581x1460028x ◽

2015 ◽

Vol 14 (01n02) ◽

pp. 1460028 ◽

Cited By ~ 2

Author(s):

Yanlei Zhao ◽

Hua Tian ◽

Junhui He ◽

Qiaowen Yang

Keyword(s):

Low Temperature ◽

Indoor Air ◽

Active Sites ◽

Harmful Effect ◽

Practical Interest ◽

Catalytic Performance ◽

Air Pollutant ◽

Ordered Mesoporous ◽

Formaldehyde Oxidation ◽

Catalytic Performances

Formaldehyde is regarded as the major indoor air pollutant. Because of harmful effect on human health, its emission abatement is of significant practical interest. We report here excellent low-temperature catalytic performances of mesoporous MnO x - CeO 2 catalysts in the process of formaldehyde oxidation. These MnO x - CeO 2 catalysts were synthesized by a "nanocasting" method using SBA-15 as hard template. TEM images showed that the as-fabricated MnO x - CeO 2 composites possess well-ordered mesoporous architectures. Results of catalytic tests revealed that mesoporous MnO x - CeO 2 nanocomposites have excellent low-temperature catalytic activity for formaldehyde oxidation, the temperature for 100% formaldehyde conversion can be as low as 65°C over these noble-metal-free mesoporous catalysts. The excellent catalytic performance is attributed to their ordered mesoporous structures that expose abundant active sites to formaldehyde molecules.

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Silica-supported Cu–Pt bimetallic catalysts for liquid-phase diethyl oxalate hydrogenation

Canadian Journal of Chemistry ◽

10.1139/cjc-2017-0547 ◽

2018 ◽

Vol 96 (4) ◽

pp. 394-403 ◽

Cited By ~ 4

Author(s):

Wei Long ◽

Pingle Liu ◽

Yang Lv ◽

Wei Xiong ◽

Fang Hao ◽

...

Keyword(s):

Liquid Phase ◽

Photoelectron Spectroscopy ◽

Bimetallic Catalysts ◽

Nitrogen Adsorption ◽

Hydrogen Uptake ◽

Copper Catalysts ◽

Catalytic Performance ◽

Diethyl Oxalate ◽

Hydrogen Chemisorption ◽

Adsorption Desorption

Silica-supported copper catalysts were prepared by different methods, and Cu/SiO2 prepared by the urea-assisted gel method was modified with co-catalyst platinum to obtain Cu-Pt/SiO2 bimetallic catalysts. The prepared catalysts were characterized by nitrogen adsorption–desorption, XRD, TEM, hydrogen chemisorption, ammonia gas chemisorption, and X-ray photoelectron spectroscopy. The characterization results show that the modification of platinum is helpful to the reduction and dispersion of copper species, which increase the hydrogen uptake quantity and metal surface area. The 30%Cu–3.0%Pt/SiO2-6 presents the best catalytic performance in liquid-phase diethyl oxalate hydrogenation; it gives 77.32% conversion of diethyl oxalate and 94.37% selectivity to the main products under 473 K and 3.0 MPa for 4 h. A possible reaction route was also proposed.

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Carbon Dioxide Hydrogenation to Methanol over Cu/ZnO-SBA-15 Catalyst: Effect of Metal Loading

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.380.151 ◽

2017 ◽

Vol 380 ◽

pp. 151-160 ◽

Cited By ~ 2

Author(s):

Sara Faiz Hanna Tasfy ◽

Noor Asmawati Mohd Zabidi ◽

Maizatul Shima Shaharun ◽

Duvvria Subbarao ◽

Ahmed Elbagir

Keyword(s):

Catalytic Activity ◽

Carbon Source ◽

Active Sites ◽

Low Cost ◽

Fixed Bed ◽

Textural Properties ◽

Catalytic Performance ◽

Hydrogenation Reaction ◽

Supported Metal Catalysts ◽

Metal Loading

Utilization of CO2 as a carbon source to produce valuable chemicals is one of the important ways to reduce the global warming caused by increasing CO2 in the atmosphere. Supported metal catalysts are crucial to produce clean and renewable fuels and chemicals from the stable CO2 molecules. The catalytic conversion of CO2 into methanol is recently under increased scrutiny as an opportunity to be used as a low-cost carbon source. Therefore, a series of the bimetallic Cu/ZnO-based catalyst supported by SBA-15 were synthesized via an impregnation technique with different total metal loading and tested in the catalytic hydrogenation of CO2 to methanol. The morphological and textural properties of the synthesized catalysts were determined by transmission electron microscopy (TEM), temperature programmed desorption, reduction, oxidation and pulse chemisorption (TPDRO), and N2-adsorption. The CO2 hydrogenation reaction was performed in a microactivity fixed-bed system at 250oC, 2.25 MPa, and H2/CO2 ratio of 3. Experimental results showed that the catalytic structure and performance were strongly affected by the loading of the active site. Where, the catalytic activity, the methanol selectivity as well as the space-time yield increased with increasing the metal loading until it reaches the maximum values at a metal loading of 15 wt% while further addition of metal inhibits the catalytic performance. The higher catalytic activity of 14% and methanol selectivity of 92% was obtained over a Cu/ZnO-SBA-15 catalyst with a total bimetallic loading of 15 wt%. The excellent performance of 15 wt% Cu/ZnO-SBA-15 catalyst is attributed to the presence of well dispersed active sites with small particle size, higher Cu surface area, and lower catalytic reducibility.

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