MIL-101(Cr) with incorporated polypyridine zinc complexes for efficient degradation of a nerve agent simulant: spatial isolation of active sites promoting catalysis

2021 ◽  
Vol 50 (6) ◽  
pp. 1995-2000
Author(s):  
Kai Zhang ◽  
Xingyun Cao ◽  
Zhiyan Zhang ◽  
Yong Cheng ◽  
Ying-Hua Zhou
Keyword(s):  
Active Sites ◽  
Zinc Complex ◽  
Nerve Agent ◽  
Zinc Complexes ◽  
Highly Active ◽  
Spatial Isolation ◽  
Polypyridine Complexes

To achieve the spatial isolation of active sites, zinc polypyridine complexes were incorporated into MIL-101(Cr). Compared with zinc complex without MOF support, the resulting catalyst was highly active for degradation of a nerve agent simulant.

Cathodic Corrosion Activated Fe-based Nanoglass as Highly-Active and -Stable Oxygen Evolution Catalyst for Water Splitting

2021 ◽  
Author(s):  
Kaiyao Wu ◽  
Fei Chu ◽  
Yuying Meng ◽  
Kaveh Edalati ◽  
Qingsheng Gao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Amorphous Alloys ◽  
Precious Metal ◽  
Active Sites ◽  
Metal Free ◽  
Highly Active ◽  
Stable Oxygen ◽  
Surface Active

Transition metal-based amorphous alloys have attracted increasing attention as precious-metal-free electrocatalysts for oxygen evolution reaction (OER) of water splitting due to their high macro-conductivity and abundant surface active sites. However,...

Co-processing of hydrodeoxygenation and hydrodesulfurization of phenol and dibenzothiophene with NiMo/Al2O3–ZrO2 and NiMo/TiO2–ZrO2 catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jesús Andrés Tavizón Pozos ◽  
Gerardo Chávez Esquivel ◽  
Ignacio Cervantes Arista ◽  
José Antonio de los Reyes Heredia ◽  
Víctor Alejandro Suárez Toriello
Keyword(s):  
Active Sites ◽  
Reaction Rate ◽  
Supported Catalysts ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
Competition Effect ◽  
Support Interaction ◽  
Highly Active ◽  
Metal Support Interaction ◽  
Metal Support

Abstract The influence of Al2O3–ZrO2 and TiO2–ZrO2 supports on NiMo-supported catalysts at a different sulfur concentration in a model hydrodeoxygenation (HDO)-hydrodesulfurization (HDS) co-processing reaction has been studied in this work. A competition effect between phenol and dibenzothiophene (DBT) for active sites was evidenced. The competence for the active sites between phenol and DBT was measured by comparison of the initial reaction rate and selectivity at two sulfur concentrations (200 and 500 ppm S). NiMo/TiO2–ZrO2 was almost four-fold more active in phenol HDO co-processed with DBT than NiMo/Al2O3–ZrO2 catalyst. Consequently, more labile active sites are present on NiMo/TiO2–ZrO2 than in NiMo/Al2O3–ZrO2 confirmed by the decrease in co-processing competition for the active sites between phenol and DBT. DBT molecules react at hydrogenolysis sites (edge and rim) preferentially so that phenol reacts at hydrogenation sites (edge and edge). However, the hydrogenated capacity would be lost when the sulfur content was increased. In general, both catalysts showed similar functionalities but different degrees of competition according to the highly active NiMoS phase availability. TiO2–ZrO2 as the support provided weaker metal-support interaction than Al2O3–ZrO2, generating a larger fraction of easily reducible octahedrally coordinated Mo- and Ni-oxide species, causing that NiMo/TiO2–ZrO2 generated precursors of MoS2 crystallites with a longer length and stacking but with a higher degree of Ni-promotion than NiMo/Al2O3–ZrO2 catalyst.

scholarly journals Atomically dispersed nickel as coke-resistant active sites for methane dry reforming

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohcin Akri ◽  
Shu Zhao ◽  
Xiaoyu Li ◽  
Ketao Zang ◽  
Adam F. Lee ◽  
...  
Keyword(s):  
Active Sites ◽  
Large Scale ◽  
Low Cost ◽  
Coke Formation ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Highly Active ◽  
Catalytic Sites ◽  
Earth Abundant ◽  
Poor Stability

AbstractDry reforming of methane (DRM) is an attractive route to utilize CO2 as a chemical feedstock with which to convert CH4 into valuable syngas and simultaneously mitigate both greenhouse gases. Ni-based DRM catalysts are promising due to their high activity and low cost, but suffer from poor stability due to coke formation which has hindered their commercialization. Herein, we report that atomically dispersed Ni single atoms, stabilized by interaction with Ce-doped hydroxyapatite, are highly active and coke-resistant catalytic sites for DRM. Experimental and computational studies reveal that isolated Ni atoms are intrinsically coke-resistant due to their unique ability to only activate the first C-H bond in CH4, thus avoiding methane deep decomposition into carbon. This discovery offers new opportunities to develop large-scale DRM processes using earth abundant catalysts.

scholarly journals Ultrasonic-assisted preparation of highly active Co3O4/MCM-41 adsorbent and its desulfurization performance for low H2S concentration gas

RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 30214-30222
Author(s):  
Bolong Jiang ◽  
Jiaojing Zhang ◽  
Yanguang Chen ◽  
Hua Song ◽  
Tianzhen Hao ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Highly Active ◽  
Ultrasonic Assisted ◽  
Sulfur Capacity ◽  
Mcm 41

Co3O4/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.

scholarly journals Nitrogen-Doped Sponge Ni Fibers as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaili Zhang ◽  
Xinhui Xia ◽  
Shengjue Deng ◽  
Yu Zhong ◽  
Dong Xie ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Photoelectron Spectroscopy ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
High Performance ◽  
Active Phase ◽  
X Ray ◽  
Highly Active ◽  
N Doping ◽  
Energy Conversion Devices

Abstract Controllable synthesis of highly active micro/nanostructured metal electrocatalysts for oxygen evolution reaction (OER) is a particularly significant and challenging target. Herein, we report a 3D porous sponge-like Ni material, prepared by a facile hydrothermal method and consisting of cross-linked micro/nanofibers, as an integrated binder-free OER electrocatalyst. To further enhance the electrocatalytic performance, an N-doping strategy is applied to obtain N-doped sponge Ni (N-SN) for the first time, via NH3 annealing. Due to the combination of the unique conductive sponge structure and N doping, the as-obtained N-SN material shows improved conductivity and a higher number of active sites, resulting in enhanced OER performance and excellent stability. Remarkably, N-SN exhibits a low overpotential of 365 mV at 100 mA cm−2 and an extremely small Tafel slope of 33 mV dec−1, as well as superior long-term stability, outperforming unmodified sponge Ni. Importantly, the combination of X-ray photoelectron spectroscopy and near-edge X-ray adsorption fine structure analyses shows that γ-NiOOH is the surface-active phase for OER. Therefore, the combination of conductive sponge structure and N-doping modification opens a new avenue for fabricating new types of high-performance electrodes with application in electrochemical energy conversion devices.

Highly Active Pt/BN Catalysts for Propane Combustion: The Roles of Support and Reactant-Induced Evolution of Active Sites

ACS Catalysis ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 1472-1481 ◽  
Author(s):  
Yan-Rong Liu ◽  
Xue Li ◽  
Wen-Min Liao ◽  
Ai-Ping Jia ◽  
Yue-Juan Wang ◽  
...  
Keyword(s):  
Active Sites ◽  
Propane Combustion ◽  
Highly Active

scholarly journals Highly Active CuFeAl-containing Catalysts for Selective Hydrogenation of Furfural to Furfuryl Alcohol

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 816 ◽  
Author(s):  
Svetlana A. Selishcheva ◽  
Andrey A. Smirnov ◽  
Alexander V. Fedorov ◽  
Olga A. Bulavchenko ◽  
Andrey A. Saraev ◽  
...  
Keyword(s):  
Furfuryl Alcohol ◽  
Active Sites ◽  
Hydrogen Pressure ◽  
Batch Reactor ◽  
Metallic Copper ◽  
Space Velocity ◽  
Oxide Content ◽  
X Ray Diffraction ◽  
Highly Active ◽  
Xrd Method

CuFe-containing catalysts with different copper oxide content were prepared by fusion of metal salts. The obtained catalyst showed high activity in the hydrogenation of furfural to furfuryl alcohol (FA) in the batch reactor in the presence of isopropanol as a solvent at a temperature of 100 °C and a hydrogen pressure of 6.0 MPa. The yield of FA and furfural conversion are 97% and 98%, respectively. In the solvent-free reaction in the flow-type reactor; the most active catalyst Cu20Fe66Al14 leads to the 96% formation of FA with 100% conversion of furfural at liquid hourly space velocity (LHSV) = 1 h−1; 160 °C and a hydrogen pressure of 5.0 MPa during 30 h. According to the X-ray diffraction (XRD) method, the active component of the spent and fresh Cu20Fe66Al14 catalyst is the same and is represented by metallic copper and Fe3O4-type spinel. Using different methods, the formation of active sites was investigated.

Fluoro-functionalized polymeric N-heterocyclic carbene-zinc complexes: efficient catalyst for formylation and methylation of amines with CO2 as a C1-building block

RSC Advances ◽  
2015 ◽  
Vol 5 (25) ◽  
pp. 19613-19619 ◽  
Author(s):  
Zhen-Zhen Yang ◽  
Bo Yu ◽  
Hongye Zhang ◽  
Yanfei Zhao ◽  
Guipeng Ji ◽  
...  
Keyword(s):  
Building Block ◽  
Zinc Complex ◽  
Zinc Complexes ◽  
Efficient Catalyst

A heterogeneous fluoro-functionalized polymeric N-heterocyclic carbene-zinc complex (F-PNHC-Zn) was designed and prepared for the formylation and methylation of N-methylanilines using CO2 as a C1 building block in the presence of organosilane.

A strategy to unlock the potential of CrN as a highly active oxygen reduction reaction catalyst

2020 ◽  
Vol 8 (17) ◽  
pp. 8575-8585 ◽  
Author(s):  
Junming Luo ◽  
Xiaochang Qiao ◽  
Jutao Jin ◽  
Xinlong Tian ◽  
Hongbo Fan ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Active Oxygen ◽  
Highly Active ◽  
Oxygen Reduction Reaction Catalyst

The potential of CrN as highly active ORR catalyst can be unlocked by enhancing its conductivity, enriching its d electrons and enlarging the exposure of active sites.

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