A STUDY ON THE EFFECT OF PREPARATION PARAMETERS ON THE CATALYTIC PERFORMANCE AND ACTIVE COMPONENTS OF A NEW TYPE HYDRODESULFURIZATION CATALYST

Nano copper-based catalysts were prepared by co-precipitation method and the performance of catalytic hydrogenation for methyl 3-hydroxypropionate (MHP) to 1, 3-propanediol (1, 3-PDO) on the nano catalysts were studied under a high-pressure microcontinuum fixed-bed reactor. The effects of structure, texture, and composition of the catalysts on the catalytic performance were investigated by characterizing the catalysts with XRD, TG–DTG, SEM, and N 2 adsorption/desorption analysis technique. The results showed that addition of promoters enhanced the activity and selectivity of copper-based catalysts, which promoted the dispersion of the active components effectively and stabilized the active center of the catalysts. Especially, the copper-based catalyst of loaded P could restrain side-reaction effectively and improve selectivity obviously, the conversion of MHP and the selectivity of 1, 3-PDO could be 91.30% and reach 90.15%, respectively.

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Theoretical Study on Improving the Catalytic Activity of a Tungsten Carbide Surface for Hydrogen Evolution by Nonmetallic Doping

Catalysts ◽

10.3390/catal10111272 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1272

Author(s):

Ye Su ◽

Xilin Xiong ◽

Xiaoxu Wang ◽

Keke Song ◽

Yating Zhou ◽

...

Keyword(s):

Catalytic Activity ◽

Tungsten Carbide ◽

Hydrogen Evolution ◽

Hydrogen Adsorption ◽

Catalytic Performance ◽

Metal Catalyst ◽

Future Research ◽

Theoretical Support ◽

New Type ◽

Nonprecious Metal Catalyst

Tungsten carbide (WC) has received widespread attention as a new type of nonprecious metal catalyst for hydrogen evolution reaction (HER). However, it is still a challenge to improve the surface HER catalytic activity. In this work, the effects of different nonmetallic dopants on the catalytic activity and stabilities of WC (0001) surface for HER were studied by first principles methods. The effects of different types of non-metal (NM = B; N; O; P and S) and doping concentrations (ni = 25–100%) on HER catalytic activity and stability were investigated by calculating the Gibbs free energy of hydrogen adsorption (∆GH) and substitution energy. It was found that the catalytic performance can be improved by doping O and P non-metallic elements. Especially, the ∆GH with P doped is −0.04eV better than Pt (−0.085 eV), which is a potential ideal catalyst for HER. Furthermore, the electronic structure analysis was used to explore the origin of the regulation of doping on stability and catalytic activity. The results show that nonmetallic doping is an effective strategy to control the catalytic activity, which provides theoretical support for the future research of HER catalysts.

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Single-atom Sn-Zn pairs in CuO catalyst promote dimethyldichlorosilane synthesis

National Science Review ◽

10.1093/nsr/nwz196 ◽

2019 ◽

Vol 7 (3) ◽

pp. 600-608 ◽

Cited By ~ 4

Author(s):

Qi Shi ◽

Yongjun Ji ◽

Wenxin Chen ◽

Yongxia Zhu ◽

Jing Li ◽

...

Keyword(s):

Density Functional ◽

Density Functional Theory Calculations ◽

Catalytic Performance ◽

Utilization Efficiency ◽

Single Atom ◽

Electronic Interaction ◽

Active Components ◽

Functional Theory ◽

Low Concentrations ◽

Sn Substitution

Abstract Single-atom catalysts are of great interest because they can maximize the atom-utilization efficiency and generate unique catalytic properties; however, much attention has been paid to single-site active components, rarely to catalyst promoters. Promoters can significantly affect the activity and selectivity of a catalyst, even at their low concentrations in catalysts. In this work, we designed and synthesized CuO catalysts with atomically dispersed co-promoters of Sn and Zn. When used as the catalyst in the Rochow reaction for the synthesis of dimethyldichlorosilane, this catalyst exhibited much-enhanced activity, selectivity and stability compared with the conventional CuO catalysts with promoters in the form of nanoparticles. Density functional theory calculations demonstrate that single-atomic Sn substitution in the CuO surface can enrich surface Cu vacancies and promote dispersion of Zn to its atomic levels. Sn and Zn single sites as the co-promoters cooperatively generate electronic interaction with the CuO support, which further facilitates the adsorption of the reactant molecules on the surface, thereby leading to the superior catalytic performance.

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Modification of Mesoporous CaZr4(PO4)6 and its Acid Catalytic Performance

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.1851 ◽

2011 ◽

Vol 396-398 ◽

pp. 1851-1855

Author(s):

Tian Si ◽

Lin Hua Zhu

Keyword(s):

Surface Acidity ◽

Sol Gel ◽

Acid Catalyst ◽

Catalytic Performance ◽

X Ray Diffraction ◽

Reaction Conditions ◽

Catalyst Sample ◽

New Type ◽

Temperature Programmed ◽

N2 Sorption

A series of new type acid catalyst samples based on mesoporous CaZr4(PO4)6(CZP) belonging to NZP family synthesized by sol-gel method was obtained by Al, La, B incorporation in CZP or by heteropoly acid H3PW12O7•xH2O(HPW) loading on CZP, and their acid catalytic activity and selectivity were investigated by using α-pinene isomerization as a probe reaction. The phase, pore structure and surface acidity of the catalyst samples were characterized by X-ray diffraction (XRD), N2 sorption and NH3 temperature programmed desorption (NH3-TPD) respectively. The results showed that the surface acidity of CZP modified by elements incorporation and HPW loading was improved in a different extent. The conversion of α-pinene at 150 °C reached to 41 % over the catalyst sample noted as Al-CZP-0.15 in which the mole ratio of Al to Zr was 0.15. Under the same reaction conditions, the conversion of α-pinene was above 95 % over the CZP supported with 20-30wt. %HPW.

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Effects of Different Pretreatment Pressures on the Catalytic Performance of Catalyst Derived from (CO)6Co2CC(COOH)2 for Fischer-Tropsch Synthesis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.781-784.186 ◽

2013 ◽

Vol 781-784 ◽

pp. 186-189

Author(s):

Yin Yan Wang ◽

Feng Hua Bai ◽

Ang Li ◽

Bo Zhao ◽

Hai Quan Su

Keyword(s):

Catalytic Performance ◽

Tropsch Synthesis ◽

Cobalt Carbonyl ◽

Fischer Tropsch ◽

Carbonyl Clusters ◽

Fischer Tropsch Synthesis ◽

Tem Characterization ◽

Co Conversion ◽

New Type ◽

Cobalt Species

New type of Co-based catalyst was prepared using (CO)6Co2CC(COOH)2 as precursor supported on γ-Al2O3 support. The effects of pretreatment pressures on the catalysts properties and the F-T synthesis performance were investigated in details. Combined with TEM characterization technology, it was found that under different pretreatment pressures (0 MPa, 1.0 MPa, 2.0 MPa), the structure of carbonyl clusters underwent different changes. Moreover, the aggregation degree of cobalt species depends on the pretreated pressure applied. In addition, the catalytic performance of the cobalt carbonyl catalyst pretreated with different pressures was performed and both CO conversion and C5+ selectivity exhibited the order of Co2/2MPa/Al2O3 > Co2/1MPa/Al2O3 > Co2/0MPa/Al2O3.

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Lanthanum Modified Catalyst for Efficient Supply of Hydrogen through Dehydrogenation of Organic Chemical Hydrides

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.2110 ◽

2011 ◽

Vol 287-290 ◽

pp. 2110-2115

Author(s):

Gang Li Zhu ◽

Tao Chen ◽

Xue Dong Jiang ◽

Hai Liang Zhang ◽

Bo Lun Yang

Keyword(s):

Energy Dispersive Spectrometer ◽

Fixed Bed ◽

Textural Properties ◽

Nitrogen Adsorption ◽

Catalytic Performance ◽

Fixed Bed Reactor ◽

Metal Species ◽

Organic Chemical ◽

Impregnation Method ◽

Active Components

Dehydrogenation process of organic chemical hydrides was improved by modifying the catalyst of nickel-activated carbon (Ni/AC) with lanthanum (La). The catalysts were prepared in impregnation method with different amounts of La and Ni. The textural properties and morphology of catalyst were analyzed by nitrogen adsorption and transmission electron microscope equipped with energy dispersive spectrometer respectively. The effects such as metal content and granule size on the dehydrogenation of cyclohexane were investigated in fixed bed reactor. The results show that the metallic active components can be well dispersed on the support, and the elements analysis indicates the metal species tend to assemble on the surface layer rather than being distributed equally in the whole catalyst. The La modified catalyst LaNi/AC exhibited superior catalytic performance to Ni/AC and the conversion was 45% for LaNi/AC catalyst at 673K, while only 34 % for Ni/AC under the same conditions.

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Comparison of the Effect of Polypyrimidine on Catalytic Performance of Polypyrimidine/CNT as Fuel Cell Catalyst Carrier

10.3762/bxiv.2019.117.v1 ◽

2019 ◽

Author(s):

Naziermu Dongmulati ◽

Caijin Shi ◽

Xieraili Maimaitiyiming

Keyword(s):

Carbon Nanotubes ◽

Fuel Cell ◽

Active Sites ◽

Active Surface ◽

Catalytic Performance ◽

Active Surface Area ◽

Catalyst Carrier ◽

Fuel Cell Catalyst ◽

Platinum Particles ◽

New Type

A new type π-conjugated poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-methyl-4,6-pyrimidine) was prepared by Sonogashira polycondensation. A fuel cell catalyst is prepared by depositing platinum particles on carbon nanotubes which was modified with poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-methyl-4,6-pyrimidine) and the previously reported poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-amino-4,6-pyrimidine). After comparing the two catalysts, it is found that active sites and catalytic performance of catalysts are significantly influenced by the copolymer on the carbon nanotubes which was the catalysis carrier. The electrochemically active surface area (ECSA) of catalysts containing poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-methyl-4,6-pyrimidine) was calculated to be 25.5 m2 g-1, which is higher than the ECSA of the poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-amino-4,6-pyrimidine) containing catalyst (18.2 m2 g-1). And the first polymer provides better methanol oxidizability and durability than second polymer for catalyst.

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The Study on the Active Site Regulated RuOx/Sn0.2Ti0.8O2 Catalysts with Different Ru Precursors for the Catalytic Oxidation of Dichloromethane

Catalysts ◽

10.3390/catal11111306 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1306

Author(s):

Yang Yang ◽

Zhong Zheng ◽

Mengyue Kong ◽

Zhesheng Hua ◽

Zhengda Yang ◽

...

Keyword(s):

Catalytic Activity ◽

Catalytic Oxidation ◽

Active Site ◽

Catalytic Performance ◽

Active Species ◽

Utilization Efficiency ◽

Active Components ◽

Efficient Treatment ◽

Oxidation Performance ◽

Industrial Exhaust

Chlorine-containing volatile organic compounds (CVOCs) present in industrial exhaust gas can cause great harm to the human body and the environment. In order to further study the catalytic oxidation of CVOCs, an active site regulated RuOx/Sn0.2Ti0.8O2 catalyst with different Ru precursors was developed. With Dichloromethane as the model molecule, the activity test results showed that the optimization of Ru precursor using Ru colloid significantly increased the activity of the catalyst (T90 was reduced by about 90 °C when the Ru loading was 1 wt%). The analysis of characterization results showed that the improvement of the catalytic performance was mainly due to the improvement of the active species dispersion (the size of Ru cluster was reduced from 3–4 nm to about 1.3 nm) and the enhancement of the interaction between the active species and the support. The utilization efficiency of the active components was improved by nearly doubling TOF value, and the overall oxidation performance of the catalyst was also enhanced. The relationship between the Ru loading and the catalytic activity of the catalyst was also studied to better determine the optimal Ru loading. It could be found that with the increase in Ru loading, the dispersibility of RuOx species on the catalyst surface gradually decreased, despite the increase in their total amount. The combined influence of these two effects led to little change in the catalytic activity of the catalyst at first, and then a significant increase. Therefore, this research is meaningful for the efficient treatment of CVOCs and further reducing the content of active components in the catalysts.

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