Rational design of alkali-resistant catalysts for selective NO reduction with NH3

2019 ◽  
Vol 55 (66) ◽  
pp. 9853-9856 ◽  
Author(s):  
Chao Li ◽  
Zhiwei Huang ◽  
Xiaona Liu ◽  
Junxiao Chen ◽  
Weiye Qu ◽  
...  
Keyword(s):  
Active Sites ◽  
Rational Design ◽  
No Reduction ◽  
Scr Catalysts ◽  
Trapping Sites

A rationale was proposed for designing alkali-resistant SCR catalysts, which have common characteristics of separate active sites and alkali-trapping sites.

scholarly journals Phase-selective active sites on ordered/disordered titanium dioxide enable exceptional photocatalytic ammonia synthesis

2021 ◽  
Author(s):  
Jinsun Lee ◽  
Xinghui Liu ◽  
Ashwani Kumar ◽  
Yosep Hwang ◽  
Eunji Lee ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Active Sites ◽  
Rational Design ◽  
Ammonia Synthesis ◽  
Reduction Reaction ◽  
Band Structures ◽  
Electronic Band ◽  
Defect Sites ◽  
Electronic Band Structures ◽  
Reaction Routes

This work highlights the importance of a rational design for more energetically suitable nitrogen reduction reaction routes and mechanisms by regulating the electronic band structures with phase-selective defect sites.

scholarly journals Engineering single-atomic ruthenium catalytic sites on defective nickel-iron layered double hydroxide for overall water splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Layered Double Hydroxide ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
Rational Design ◽  
Single Atom ◽  
Nickel Iron ◽  
Double Hydroxide

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.

scholarly journals Kinetics of Selective Catalytic Reduction of Nitric Oxide over Pt-Cu-Zsm5 Catalyst

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Ismail Mohd Saaid ◽  
Abdul Rahman Mohamed and Subhash Bhatia
Keyword(s):  
Nitric Oxide ◽  
Selective Catalytic Reduction ◽  
Active Sites ◽  
No Reduction ◽  
Bimetallic Catalyst ◽  
Catalytic Reduction ◽  
Covalent Bond ◽  
Reaction Parameters ◽  
Heterogeneous Model ◽  
Kinetics Of

Kinetics for the selective catalytic reduction (SCR) of nitric oxide (NO) using i-C4H10 as the reducing agent over Pt-Cu-ZSM5 has been investigated in the temperature range of 200 ?C – 450 oC. Langmuir-Hinshelwood-Hougen-Watson model was proposed for kinetics of the reaction and reaction parameters were evaluated.  The heat of adsorption of NO was found to be considerably high, attributed to strong covalent bond between NO gas molecules and metal active sites.  Using reaction parameters obtained from the experiment, the heterogeneous model could form a good correlation between experimental and simulated values of NO reduction. Key Words: Reaction kinetics, Selective catalytic reduction, NO reduction, Bimetallic catalyst, H-ZSM-5 zeolite.

scholarly journals Engineering active sites on hierarchical transition bimetal oxides/sulfides heterostructure array enabling robust overall water splitting

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Yanxue Zhang ◽  
Yunzhen Wu ◽  
Junfeng Gao ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Active Sites ◽  
Rational Design ◽  
Large Scale ◽  
Grand Challenge ◽  
Long Term Stability ◽  
Large Current ◽  
Electrode Cell ◽  
Large Current Density ◽  
Current Densities

Abstract Rational design of the catalysts is impressive for sustainable energy conversion. However, there is a grand challenge to engineer active sites at the interface. Herein, hierarchical transition bimetal oxides/sulfides heterostructure arrays interacting two-dimensional MoOx/MoS2 nanosheets attached to one-dimensional NiOx/Ni3S2 nanorods were fabricated by oxidation/hydrogenation-induced surface reconfiguration strategy. The NiMoOx/NiMoS heterostructure array exhibits the overpotentials of 38 mV for hydrogen evolution and 186 mV for oxygen evolution at 10 mA cm−2, even surviving at a large current density of 500 mA cm−2 with long-term stability. Due to optimized adsorption energies and accelerated water splitting kinetics by theory calculations, the assembled two-electrode cell delivers the industrially relevant current densities of 500 and 1000 mA cm−2 at record low cell voltages of 1.60 and 1.66 V with excellent durability. This research provides a promising avenue to enhance the electrocatalytic performance of the catalysts by engineering interfacial active sites toward large-scale water splitting.

scholarly journals Rational Design of Alkali-Resistant NO Reduction Catalysts using a Stable Hexagonal V-Doped MoO3 Support for Alkali Trapping

ChemCatChem ◽  
2018 ◽  
Vol 10 (18) ◽  
pp. 3926-3926
Author(s):  
Xiaona Liu ◽  
Jiayi Gao ◽  
Yaxin Chen ◽  
Chao Li ◽  
Junxiao Chen ◽  
...  
Keyword(s):  
Rational Design ◽  
No Reduction ◽  
Reduction Catalysts

Rational design of atomically dispersed nickel active sites in β-Mo2C for the hydrogen evolution reaction at all pH values

2018 ◽  
Vol 54 (71) ◽  
pp. 9901-9904 ◽  
Author(s):  
Ting Ouyang ◽  
An-Na Chen ◽  
Zhen-Zhao He ◽  
Zhao-Qing Liu ◽  
Yexiang Tong
Keyword(s):  
Synergistic Effect ◽  
Electrochemical Properties ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Rational Design ◽  
Efficient Catalyst ◽  
Ph Values ◽  
Ni Species

Atomically dispersed Ni in β-Mo2C (Ni/β-Mo2C) is designed as an efficient catalyst for the HER at all pH values. The remarkable electrochemical properties of Ni/β-Mo2C are mainly attributed to the synergistic effect between atomically dispersed Ni species and β-Mo2C.

scholarly journals In Situ DRIFTS Investigation on CeOx Catalyst Supported by Fly-Ash-Made Porous Cordierite Ceramics for Low-Temperature NH3-SCR of NOX

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 496 ◽  
Author(s):  
Shaoxin Wang ◽  
Ziwei Chen ◽  
Beini He ◽  
Zheng Yan ◽  
Hao Wang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Supported Catalyst ◽  
Nh3 Scr ◽  
Scr Catalysts ◽  
Cordierite Ceramics ◽  
Porous Cordierite

A series of CeOx catalysts supported by commercial porous cordierite ceramics (CPCC) and synthesized porous cordierite ceramics (SPCC) from fly ash were prepared for selective catalytic reduction of NOx with ammonia (NH3-SCR). A greater than 90% NOx conversion rate was achieved by the SPCC supported catalyst at 250–300 °C when the concentration of loading precursor was 0.6 mol/L (denoted as 0.6Ce/SPCC), which is more advantageous than the CPCC supported ones. The EDS mapping results reveal the existence of evenly distributed impurities on the surface of SPCC, which hence might be able to provide more attachment sites for CeOx particles. Further measurements with temperature programmed reduction by hydrogen (H2-TPR) demonstrate more reducible species on the surface of 0.6Ce/SPCC, thus giving rise to better NH3-SCR performance at a low-temperature range. The X-ray photoelectron spectroscopy (XPS) analyses reveal that the Ce atom ratio is higher in 0.6Ce/SPCC, indicating that a higher concentration of catalytic active sites could be found on the surface of 0.6Ce/SPCC. The in situ diffused reflectance infrared fourier transform spectroscopy (DRIFTS) results indicate that the SCR reactions over 0.6Ce/SPCC follow both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. Hence, the SPCC might be a promising candidate to provide support for NH3-SCR catalysts, which also provide a valuable approach to recycling the fly ash.

Atomically dispersed Ni as the active site towards selective hydrogenation of nitroarenes

2019 ◽  
Vol 21 (3) ◽  
pp. 704-711 ◽  
Author(s):  
Fan Yang ◽  
Minjian Wang ◽  
Wei Liu ◽  
Bin Yang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Noble Metal ◽  
Catalytic Hydrogenation ◽  
Selective Hydrogenation ◽  
Porous Carbon ◽  
Active Site ◽  
Active Sites ◽  
Rational Design ◽  
Metal Free

Noble-metal-free catalytic hydrogenation of nitroarenes is achieved through the rational design of atomically dispersed Ni sites on N-doped porous carbon. The outstanding activity of the catalyst originates from the atomic dispersion of Ni active sites with a high Ni–N3 content.

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