scholarly journals Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNOx-SCR

2012 ◽  
Vol 3 ◽  
pp. 667-673 ◽  
Author(s):  
Thomas Simons ◽  
Ulrich Simon
Keyword(s):  
Reaction System ◽  
In Situ Monitoring ◽  
Full Description ◽  
Reaction Monitoring ◽  
Proof Of Concept ◽  
Temperature Dependent ◽  
Reaction Conditions ◽  
Thermally Induced ◽  
Insight Into

In a proof-of-concept study we demonstrate in situ reaction monitoring of DeNOx-SCR on proton-conducting zeolites serving as catalyst and gas sensor at the same time. By means of temperature-dependent impedance spectroscopy we found that the thermally induced NH3 desorption in H-form and in Fe-loaded zeolite H-ZSM-5 follow the same process, while a remarkable difference under DeNOx-SCR reaction conditions was found. The Fe-loaded catalyst shows a significantly lower onset temperature, and time-dependent measurements suggest different SCR reaction mechanisms for the two catalysts tested. These results may help in the development of catalysts for the reduction of NOx emissions and ammonia consumption, and provide insight into the elementary catalytic process promoting a full description of the NH3-SCR reaction system.

In situ loading of well-dispersed silver nanoparticles on nanocrystalline magnesium oxide for real-time monitoring of catalytic reactions by surface enhanced Raman spectroscopy

Nanoscale ◽  
2015 ◽  
Vol 7 (40) ◽  
pp. 16952-16959 ◽  
Author(s):  
Kaige Zhang ◽  
Gongke Li ◽  
Yuling Hu
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Catalytic Reactions ◽  
Reaction Intermediates ◽  
Reaction Conditions ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Nanocrystalline Magnesium Oxide ◽  
Insight Into

The surface-enhanced Raman spectroscopy (SERS) technique is of great importance for insight into the transient reaction intermediates and mechanistic pathways involved in heterogeneously catalyzed chemical reactions under actual reaction conditions, especially in water.

In Situ Monitoring of Thermally Induced Effects in Nickel-Rich Layered Oxide Cathode Materials at the Atomic Level

2020 ◽  
Vol 12 (51) ◽  
pp. 57047-57054
Author(s):  
Anuj Pokle ◽  
Shamail Ahmed ◽  
Simon Schweidler ◽  
Matteo Bianchini ◽  
Torsten Brezesinski ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Atomic Level ◽  
In Situ Monitoring ◽  
Thermally Induced ◽  
Layered Oxide ◽  
Oxide Cathode

In Situ Monitoring Potential-Dependent Electrochemical Process by Liquid NMR Spectroelectrochemical Determination: A Proof-of-Concept Study

2017 ◽  
Vol 89 (7) ◽  
pp. 3810-3813 ◽  
Author(s):  
Shuo-Hui Cao ◽  
Zu-Rong Ni ◽  
Long Huang ◽  
Hui-Jun Sun ◽  
Biao Tang ◽  
...  
Keyword(s):  
Electrochemical Process ◽  
In Situ Monitoring ◽  
Proof Of Concept ◽  
Concept Study

scholarly journals Selective Nitration of Chlorobenzene by NO2 in the Alkali Zeolite NaZSM-5

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Scott J. Kirkby
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Temperature Dependent ◽  
Reaction Conditions ◽  
Cation Site ◽  
Zeolite Lattice ◽  
Reaction Proceeds ◽  
Ft Ir ◽  
Electron Donation

Chlorobenzene was reacted with NO2, in the initially acid-free zeolite NaZSM-5, to yield para-chloronitrobenzene exclusively. The precursors were loaded sequentially into self-supporting pellets of the zeolite, contained within a stainless steel cell, from the gas phase. The reaction proceeds spontaneously at room temperature. It is, however, very temperature dependent and effectively ceases at zero degrees Celsius. The reaction was monitored in situ using FT-IR. The active nitrating agent is formed from the partial electron donation by the NO2 to the Na+ cations present in the zeolite lattice. Under the reaction conditions, chlorobenzene is not readily mobile through the pore system; thus, only the molecules adsorbed near a cation site react to form para-chloronitrobenzene.

Qualitative Identification of Alloys of Precious Metals by Means of Adaptive Changes the Mode Polarization

2016 ◽  
Vol 843 ◽  
pp. 173-177
Author(s):  
S.M. Lipkin ◽  
V.S. Elsukov ◽  
V.I. Lachin
Keyword(s):  
Reaction System ◽  
Precious Metals ◽  
Optimization Method ◽  
Linear Regression Coefficient ◽  
Reaction Conditions ◽  
Adaptive Adjustment ◽  
Optimal Values ◽  
Adjustment System ◽  
Significant Factors

This article is about adaptive adjustment of reaction conditions in local electrochemical rapid analysis. These conditions include in-situ current correction during pulse chronopotentiogram mesuarements. Optimal values of correction parameters were obtained by steep ascent optimization method. Treatment of gold alloys chronopotentiograms was made by the decomposition modeling method. As a result, application of a probe current adjustment system to chronopotentiometry process allows more than 3-time increase in reproducibility of experimental results. The most significant factors in optimizing the parameters of the proposed system are the slope of the linear regression coefficient of the reaction system.

scholarly journals Muscle-on-a-chip with an on-site multiplexed biosensing system for in situ monitoring of secreted IL-6 and TNF-α

Lab on a Chip ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 2568-2580 ◽  
Author(s):  
María A. Ortega ◽  
Xiomara Fernández-Garibay ◽  
Albert G. Castaño ◽  
Francesco De Chiara ◽  
Alejandro Hernández-Albors ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Tissue ◽  
Skeletal Muscle Tissue ◽  
In Situ Monitoring ◽  
Proof Of Concept ◽  
Cell Stimulation ◽  
Tnf Α ◽  
Analyte Detection ◽  
Biosensing System

We present an integrated microdevice capable of simultaneous, in situ cell stimulation and analyte detection. As a proof of concept, the detection of secreted cytokines from an engineered 3D skeletal muscle tissue was measured.

Monitoring thermally induced structural deformation and framework decomposition of ZIF-8 through in situ temperature dependent measurements

2017 ◽  
Vol 19 (40) ◽  
pp. 27178-27183 ◽  
Author(s):  
Ben Xu ◽  
Yingjie Mei ◽  
Zhenyu Xiao ◽  
Zixi Kang ◽  
Rongming Wang ◽  
...  
Keyword(s):  
Structural Deformation ◽  
Lattice Expansion ◽  
Temperature Dependent ◽  
Thermally Induced ◽  
Deformation Stage ◽  
Expansion Stage ◽  
Transition Stages

ZIF-8 undergoes three transition stages, which are lattice expansion stage, “reversible” structural deformation stage, and decomposition/collapse stage.

scholarly journals Synthesis of Linoleic Acid 13-Hydroperoxides from Safflower Oil Utilizing Lipoxygenase in a Coupled Enzyme System with In-Situ Oxygen Generation

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1119
Author(s):  
Valentin Gala Marti ◽  
Anna Coenen ◽  
Ulrich Schörken
Keyword(s):  
Linoleic Acid ◽  
Candida Rugosa ◽  
Reaction System ◽  
Lag Phase ◽  
Safflower Oil ◽  
Reaction Conditions ◽  
Free System ◽  
Enzyme Cascade ◽  
Oil Hydrolysis

Linoleic acid hydroperoxides are versatile intermediates for the production of green note aroma compounds and bifunctional ω-oxo-acids. An enzyme cascade consisting of lipoxygenase, lipase and catalase was developed for one-pot synthesis of 13-hydroperoxyoctadecadienoic acid starting from safflower oil. Reaction conditions were optimized for hydroperoxidation using lipoxygenase 1 from Glycine max (LOX-1) in a solvent-free system. The addition of green surfactant Triton CG-110 improved the reaction more than two-fold and yields of >50% were obtained at linoleic acid concentrations up to 100 mM. To combine hydroperoxidation and oil hydrolysis, 12 lipases were screened for safflower oil hydrolysis under the reaction conditions optimized for LOX-1. Lipases from Candida rugosa and Pseudomonas fluorescens were able to hydrolyze safflower oil to >75% within 5 h at a pH of 8.0. In contrast to C. rugosa lipase, the enzyme from P. fluorescens did not exhibit a lag phase. Combination of P. fluorescens lipase and LOX-1 worked well upon LOX-1 dosage and a synergistic effect was observed leading to >80% of hydroperoxides. Catalase from Micrococcus lysodeikticus was used for in-situ oxygen production with continuous H2O2 dosage in the LOX-1/lipase reaction system. Foam generation was significantly reduced in the 3-enzyme cascade in comparison to the aerated reaction system. Safflower oil concentration was increased up to 300 mM linoleic acid equivalent and 13-hydroperoxides could be produced in a yield of 70 g/L and a regioselectivity of 90% within 7 h.

Sign in / Sign up

Export Citation Format

Share Document