@article { ISI:000250234900007, title = {Fabrication of an effusive molecular beam instrument for surface reaction kinetics - CO oxidation and NO reduction on Pd(111) surfaces}, journal = {Catalysis Letters}, volume = {119}, number = {1-2}, year = {2007}, month = {NOV}, pages = {50-58}, publisher = {SPRINGER}, type = {Article}, address = {233 SPRING STREET, NEW YORK, NY 10013 USA}, abstract = {

A simple molecular beam instrument (MBI) was fabricated for measuring the fundamental parameters in catalysis such as, sticking coefficient, transient and steady state kinetics and reaction mechanism of gas/vapor phase reactions on metal surfaces. Important aspects of MBI fabrication are given in detail. Nitric oxide (NO) decomposition and NO reduction with carbon monoxide (CO) on Pd(111) surfaces were studied. Interesting results were observed for the above reactions and they support the efficiency of the MBI to derive the fundamental parameters of adsorption and catalysis. Sustenance of CO oxidation at 400 K is dependent mostly on the absence of CO-poisoning; apparently, CO + O recombination is the rate determining step \<= 400 K. NO adsorption measurements on Pd(111) surface clearly indicating a typical precursor kinetics. Displacement of the chemisorbed CO by NO on Pd(111) surfaces was observed directly with NO + CO beams in the transient kinetics. It is also relatively easy to identify the rate-determining step directly from the MBI data and the same was demonstrated for the above reactions.

}, keywords = {carbon monoxide, catalysis, kinetics, molecular beam, nitric oxide, Pd(111)}, issn = {1011-372X}, doi = {10.1007/s10562-007-9184-8}, author = {Thirunavukkarasu, Kandasamy and Gopinath, Chinnakonda S.} } @article { ISI:000267632500006, title = {CO sensor based on polypyrrole functionalized with iron porphyrin}, journal = {Synthetic Metals}, volume = {159}, number = {11}, year = {2009}, month = {JUN}, pages = {1019-1023}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Polypyrrole (PPy) was chemically functionalized with 5,10,15,20-tetraphenyl-21H,23H-porphyrin iron(III) chloride (FeTPPCl) with special interest on noxious carbon monoxide (CO) gas in ppm level. Controlled functionalization of PPy was achieved with incorporation of various concentrations of porphyrin. The resulted semiconducting material was well characterized by different techniques such as UV-vis spectroscopy, FTIR, GFAAS, XRD, and EDAX. The functionalized polypyrrole material on interdigitated electrode was experienced an immediate increase in resistance when exposed to carbon monoxide gas at very low concentration. The CO gas interacted very fast with the FeTPPCl functionalized PPy at room temperature (RT) and then slowly saturated. The response of these materials was not unidirectional, but reverses to the original resistance level when CO was removed from the test chamber. The highest response factor (Delta R/R(0) x 100) and lowest response time (t(50)) obtained are 12 and 169s, respectively. An optimum level of doping (1 mol\% of FeTPPCl) was established for the highest sensitivity and the detection level is as low as 100ppm. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {carbon monoxide, Chemical sensor, Fe(III) porphyrin, polypyrrole}, issn = {0379-6779}, doi = {10.1016/j.synthmet.2009.01.018}, author = {Paul, Santhosh and Amalraj, Francis and Radhakrishnan, S.} } @article { ISI:000265814500012, title = {Polypyrrole functionalized with ferrocenyl derivative as a rapid carbon monoxide sensor}, journal = {Synthetic Metals}, volume = {159}, number = {5-6}, year = {2009}, month = {MAR}, pages = {415-418}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A rapid carbon monoxide detection system was developed with the electrochemical functioncalization of polypyrrole (PPy) with ferrocenylmethyltrimethylammonium iodide (FTMA-I) as a co-dopant exhibits very high sensitivity to ppm levels of carbon monoxide gas and fast recovery under normal dry room temperature conditions. The co-dopant was synthesized mainly to incorporate into PPy electrochemically to modify the properties in order to sense carbon monoxide (CO) gas. The FTMA-I doped PPy exhibited the characteristics oxidation/reduction peaks for ferrocene in its cyclic voltammograms. The modified PPy films deposited on interdigited electrodes gave rapid sensitivity within a second to 300 ppm carbon monoxide gas and good sensitivity factor was observed even at 4 mmol of the functional groups in the polymer for 300 ppm carbon monoxide gas. This material detected the CO gas concentration as low as 100 ppm. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {carbon monoxide, Chemical sensor, conducting polymer, polypyrrole}, issn = {0379-6779}, doi = {10.1016/j.synthmet.2008.10.013}, author = {Paul, Santhosh and Chavan, Nayaku and Radhakrishnan, S.} } @article { ISI:000344330800015, title = {Role of nanointerfaces in Cu- and Cu plus Au-based near-ambient-temperature CO oxidation catalysts}, journal = {ChemCatChem}, volume = {6}, number = {11}, year = {2014}, month = {NOV}, pages = {3116-3124}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Disordered mesoporous Cu-doped ceria-zirconia (Cu0.1Ce0.85Zr0.05O2), and gold deposited (Au/Cu0.1Ce0.85Zr0.05O2) catalysts were synthesized and evaluated for CO oxidation. Onset of CO oxidation activity, and 50\% (100\%) CO2 formation occurs at room temperature (RT), and 77 (120)degrees C, respectively, with Cu0.1Ce0.85Zr0.05O2. A small amount of gold on Cu0.1Ce0.85Zr0.05O2 induces the sustainable oxidation catalysis around RT. Onset of copper reduction temperature decreases from 110 degrees C on Cu0.1Ce0.85Zr0.05O2 to 48 degrees C with Au/Cu0.1Ce0.85Zr0.05O2, highlighting the direct interaction between Cu and Au through a Cu-Au interface. Au particles with a (00 1) facet deposit on an oxygen-deficient site of (111) facet of CeO2-ZrO2. Any decrease in surface Cu-content with increasing Au-content further supports the Au-Cu-Ce/Zr interface interactions. Nanointerfaces of Au clusters on Cu next to oxygen-deficient sites of CeO2-ZrO2 facilitate all the elementary steps of the CO + O-2 reaction to occur in close proximity at ambient conditions.

}, keywords = {carbon monoxide, Gold, heterogeneous catalysis, Oxidation, redox}, issn = {1867-3880}, doi = {10.1002/cctc.201402581}, author = {Gnanakumar, Edwin S. and Naik, Jarpla Madhusudhan and Manikandan, Marimuthu and Raja, Thirumalaiswamy and Gopinath, Chinnakonda S.} } @article {43814, title = {Water mediated deactivation of Co3O4 naonrods catalyst for CO oxidation and resumption of activity at and above 373 K: electronic structural aspects by NAPPES}, journal = {Journal of Physical Chemistry C}, volume = {121}, year = {2017}, month = {SEP}, pages = {20296{\textendash}20305}, type = {Journal Article}, chapter = {20296-20305}, abstract = {

The catalytic activity of the Co3O4 nanorods (NRs) for the CO oxidation reaction and the effect of water on the catalytic reaction have been explored with near-ambient pressure photoelectron spectroscopy (NAPPES) and mass spectral analysis. Comparative NAPPES studies have been employed to understand the elucidation of the catalytic reaction pathway and the evolution of various surface species. The results confirm the suppression of the CO oxidation activity on the Co3O4 NRs in the presence of water vapor. Various type of surface species, such as CO(ads), hydroxyl, carbonate, formate, are found to be present on the catalyst surface depending on the reaction conditions. Vibrational features of CO, O-2, and CO, were observed and shift in binding energy of these features under the reaction conditions directly suggests a change in work function of the catalyst surface. Under dry conditions, CO couples with labile 0 atoms to form CO2; however, under wet conditions, CO predominantly interacts with surface OH groups resulting in the formation of carbonate and formate intermediates. In situ studies of oxidation of CO on Co3O4 shows that CO oxidation depends not only on surface Co3+ concentration but also influenced by Co-3/Co{\textquoteright} ratio on the catalyst surface. The carbonate was found to be a reaction inhibitor at room temperature; however, it acts as an active intermediate at 375 K and above. Above the boiling point of water, Co3O4 NR surfaces begin to show the oxidation activity even in the presence of water vapor. The intrinsic role of intermediate species was used to derive a possible reaction mechanism under different reaction conditions.

}, keywords = {Ambinent-temprature, carbon monoxide, Gas Shift, H Activation, In-situ, Low-temprature oxidation, Molecular-beam, Performance enhancement, Ray Photoelectron-Spectroscopyu, Thin-films}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.7b05480}, author = {Jain, Ruchi and Reddy, Kasala Prabhakar and Ghosalya, Manoj Kumar and Gopinath, Chinnakonda S.} } @article {46874, title = {Mechanistic aspects of methanol electro-oxidation reaction through cyclic voltammetry: is it correct to blame carbon monoxide for catalyst poisoning?}, journal = {Energy Technology}, volume = {8}, year = {2020}, month = {MAY}, pages = {1900955}, type = {Article}, abstract = {

The mechanism of the methanol oxidation reaction is revisited using systematic cyclic voltammetric studies. These studies clearly indicate that the peak during the cathodic scan belongs mainly to electro-oxidation of the carbon monoxide, and that only a fraction of this carbon monoxide remains adsorbed on the electrode, contrary to what previous reports suggested. More details can be found in article number by Bhagavatula L. V. Prasad and co-workers.

}, keywords = {carbon monoxide, cyclic voltammetry, electrocatalysts, electrode poisoning, Methanol oxidation}, issn = {2194-4288}, doi = {10.1002/ente.201900955}, author = {Deshpande, Pooja S. and Chaudhari, Vijay R. and Prasad, Bhagavatula L. V.} }