On-site refreshing active species responsible for catalytic activity during cooling catalyst in H2-rich reaction atmosphere

2021 ◽  
Vol 546 ◽  
pp. 149073
Author(s):  
Yang Liu ◽  
Qi Wang ◽  
Aiai Zhang ◽  
Zeyu Chen ◽  
Xinya Wu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Species ◽  
Reaction Atmosphere

scholarly journals ZnCDs/ZnO@ZIF-8 Zeolite Composites for the Photocatalytic Degradation of Tetracycline

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 934
Author(s):  
Yong Cheng ◽  
Xiuxiu Wang ◽  
Yu Mei ◽  
Dan Wang ◽  
Changchun Ji
Keyword(s):  
Catalytic Activity ◽  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Active Species ◽  
Degradation Efficiency ◽  
Experimental Result ◽  
Porous Nanostructure ◽  
Resultant Material

Considering the photocatalytic performance of CDs, ZnO, and the unique porous nanostructure and stability of ZIF-8, we prepared ZnCDs/ZnO@ZIF-8 zeolite composites. The resultant material represented an enhanced ability for the photodegradation of TC compared with that of ZnCDs and ZnO. The photocatalytic degradation efficiency reached over 85%. The catalytic activity of the composites was maintained after four cycles. The experimental result indicated that ×O2 radical was the active species in the reaction.

Ni, beyond thermodynamic tuning, maintains the catalytic activity of V species in Ni3(VO4)2 doped MgH2

2021 ◽  
Vol 9 (13) ◽  
pp. 8341-8349
Author(s):  
Jiahe Zang ◽  
Shaofei Wang ◽  
Rongrun Hu ◽  
Han Man ◽  
Jichao Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Storage ◽  
Active Species ◽  
Ni Alloy

A bimetallic oxide Ni3(VO4)2 has been synthesized to catalyze the hydrogen storage reaction of MgH2. The formation of the Mg2Ni alloy and the kinetic modulation of V results in a dehydrogenation temperature of 210 °C. The NiV2O4 intermediate active species is also detected.

Enhancing catalytic activity and stability for CO2 methanation on Ni@MOF-5 via control of active species dispersion

2015 ◽  
Vol 51 (9) ◽  
pp. 1728-1731 ◽  
Author(s):  
Wenlong Zhen ◽  
Bo Li ◽  
Gongxuan Lu ◽  
Jiantai Ma
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
High Stability ◽  
Active Catalyst ◽  
Active Species ◽  
Co2 Methanation ◽  
Long Term Stability ◽  
Uniform State ◽  
Highly Dispersed

A novel high active catalyst Ni@MOF-5 showed unexpected higher activity under the low temperature for CO2 methanation. The characterization results indicated that Ni was in highly dispersed uniform state over MOF-5. This catalyst performed high stability and showed almost no deactivation in long term stability tests up to 100 h.

scholarly journals Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η5-Cp)Pd(IPr)Cl with (η3-cinnamyl)Pd(IPr)(Cl) and (η3-1-t-Bu-indenyl)Pd(IPr)(Cl)

2015 ◽  
Vol 11 ◽  
pp. 2476-2486 ◽  
Author(s):  
Patrick R Melvin ◽  
Nilay Hazari ◽  
Hannah M C Lant ◽  
Ian L Peczak ◽  
Hemali P Shah
Keyword(s):  
Catalytic Activity ◽  
Comparative Studies ◽  
Active Species ◽  
Highly Active ◽  
Supported Pd

Complexes of the type (η3-allyl)Pd(L)(Cl) and (η3-indenyl)Pd(L)(Cl) are highly active precatalysts for the Suzuki–Miyaura reaction. Even though allyl and indenyl ligands are similar to cyclopentadienyl (Cp) ligands, there have been no detailed comparative studies exploring the activity of precatalysts of the type (η5-Cp)Pd(L)(Cl) for Suzuki–Miyaura reactions. Here, we compare the catalytic activity of (η5-Cp)Pd(IPr)(Cl) (IPr = 1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene, Cp) with two commercially available catalysts (η3-cinnamyl)Pd(IPr)(Cl) (Cin) and (η3-1-t-Bu-indenyl)Pd(IPr)(Cl) ( tBu Ind). We show that Cp gives slightly better catalytic activity than Cin, but significantly inferior activity than tBu Ind. This order of activity is rationalized by comparing the rates at which the precatalysts are activated to the monoligated Pd(0) active species along with the tendency of the starting precatalysts to comproportionate with monoligated Pd(0) to form inactive Pd(I) dimers. As part of this work the Cp supported Pd(I) dimer (μ-Cp)(μ-Cl)Pd2(IPr)2 (Cp Dim ) was synthesized and crystallographically characterized. It does not readily disproportionate to form monoligated Pd(0) and consequently Cp Dim is a poor catalyst for the Suzuki–Miyaura reaction.

The effect of different metal oxides on the catalytic activity of a Co3O4 catalyst for toluene combustion: importance of the structure–property relationship and surface active species

2019 ◽  
Vol 43 (27) ◽  
pp. 10868-10877 ◽  
Author(s):  
Xuejun Zhang ◽  
Min Zhao ◽  
Zhongxian Song ◽  
Heng Zhao ◽  
Wei Liu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metal Oxides ◽  
Catalytic Oxidation ◽  
Active Species ◽  
Active Oxygen ◽  
Redox Cycle ◽  
Structure Property ◽  
Property Relationship ◽  
Structure Property Relationship ◽  
Surface Active

The Co–La catalyst was used to the catalytic oxidation of toluene. The LaCoO3 perovskite was detected. The abundance of Co3+ and active oxygen contributed synergistically to the redox cycle reaction, which could improve the catalytic activity.

scholarly journals Reduction of Nitrobenzene to Aniline by CO/H2O in the Presence of Palladium Nanoparticles

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 404 ◽  
Author(s):  
Agnieszka Krogul-Sobczak ◽  
Jakub Cedrowski ◽  
Patrycja Kasperska ◽  
Grzegorz Litwinienko
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
Metallic Nanoparticles ◽  
Active Species ◽  
Catalytic Cycle ◽  
Heterocyclic Ligands ◽  
Aromatic Nitrocompounds ◽  
First Time ◽  
Transient Intermediate

The transformation of aromatic nitrocompounds into amines by CO/H2O is catalyzed by palladium(II) complexes. Recently, we have proposed that the catalytic cycle includes Pd0 as the transient intermediate and herein, for the first time, we describe the application of palladium nanoparticles (PdNPs) stabilized by monodentate N-heterocyclic ligands as nanocatalysts facilitating the reduction of Ar–NO2 into Ar–NH2 by CO/H2O. Among the series—Pd(II) complexes, PdNPs and commercial Pdblack—the highest catalytic activity was observed for PdNPs (3.0 ± 0.5 nm) stabilized by 4-Me-pyridine in the presence of 2-Cl-pyridine. The results may be helpful for mechanistic considerations on the role of metallic nanoparticles as active species in other organic processes.

Effect of Preparation Methods on Ti-PILCs Catalysts in Selective Catalytic Reduction of NO by Propylene

2014 ◽  
Vol 1033-1034 ◽  
pp. 90-94 ◽  
Author(s):  
Qi Ying Wang ◽  
Zi Li Liu ◽  
Jun Rong Wu
Keyword(s):  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Active Species ◽  
Bet Surface Area ◽  
High Catalytic Activity ◽  
Incipient Wetness Impregnation ◽  
Distribution Analysis ◽  
Preparation Methods ◽  
Reduction Of No

Different Cu-loading pillared clays catalysts were studied in selective catalytic reduction of NO by propylene. The catalyst prepared by incipient wetness impregnation (Cu/Ti-PILCs) had better catalytic activity and stability than that prepared by ion-exchanged method (Cu-Ti-PILCs). Cu/Ti-PILCs has higher BET surface area than Cu-Ti-PILCs. Pore size distribution analysis and XRD showed that Cu species dispersed well in Cu/Ti-PILCs but formed conglomeration in Cu-Ti-PILCs. TPR showed that Cu2+ species were the main active species on the Cu/Ti-PILCs, which was responsible for the high catalytic activity of catalyst.

Modulating the Water oxidation Catalytic activity of Iridium Complexes by Functionalizing the Cp*-Ancillary Ligand: Hints on the Nature of the Active Species

2021 ◽  
Author(s):  
Giordano Gatto ◽  
Alice De Palo ◽  
Fabio Marchetti ◽  
Ana C. Carrasco ◽  
Guido Pampaloni ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Water Oxidation ◽  
Active Species ◽  
Iridium Complexes ◽  
Ancillary Ligand

The catalytic activity toward NaIO4 driven water oxidation of a series of [RCp*IrCl(µ-Cl)]2 dimeric precursors, containing tetramethylcyclopentadienyl ligands with a variable R substituent (H, 1; Me, 2; Et, 3; nPr,...

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