{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,2]],"date-time":"2025-11-02T19:56:44Z","timestamp":1762113404306,"version":"build-2065373602"},"reference-count":11,"publisher":"SAE International","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["SAE Int. J. Engines"],"abstract":"<div class=\"section abstract\"><div class=\"htmlview paragraph\">Transport limitations inside the porous washcoat layer have an important influence in the light-off and overall conversions even in the case of relatively thin layers used in automotive three way catalysts (TWC). The porous structure of the washcoat layer is controlled at two levels: i) at the level of mesoporous structure, which can be determined by the use of specific synthesis techniques (<i>e.g.<\/i>, sol-gel or pore-templating method), and ii) at the level of macroporous structure, which is influenced by the particle size distribution of mesoporous in a slurry that has undergone a specific thermal treatment. This paper investigates the influence of the washcoat structure in the performance of automotive TWC. Furthermore, the article presents a method that allows to quantify the magnitude of the reaction resistance (chemical kinetics), internal mass transfer resistance (washcoat diffusion), and external mass transfer resistance on the TWC conversions. From experimental data gathered at different operating temperatures (from light-off to 1100 K) and applying the developed methodology for resistances quantification, it was found that the internal mass transfer limitations play a major role in the TWC conversions. The main conclusions from this study are: i) the effective diffusivity strongly depends on the washcoat layer structure, which in turn depends on its preparation process; ii) the resistance quantification analysis reveals that the lower effective diffusivity interval is more adequate for the TWC used in the present investigation, which also indicates that the TWC washcoat has a low percentage of macropores; and iii) to decrease the relevance of the internal mass transfer limitation requires an increase in the effective diffusivity and\/or a thinner washcoat layer.<\/div><\/div><\/jats:p>","DOI":"10.4271\/2013-24-0166","type":"journal-article","created":{"date-parts":[[2013,9,9]],"date-time":"2013-09-09T06:02:08Z","timestamp":1378706528000},"page":"1846-1854","source":"Crossref","is-referenced-by-count":4,"title":["Influence of the Washcoat Structure in the Performance of Automotive Three Way Catalysts"],"prefix":"10.4271","volume":"06","author":[{"given":"Helder","family":"Santos","sequence":"first","affiliation":[{"name":"Instituto Polit\u00e9cnico de Leiria"}]},{"given":"Jo\u00e3o","family":"Pires","sequence":"additional","affiliation":[{"name":"Instituto Polit\u00e9cnico de Leiria"}]},{"given":"M\u00e1rio","family":"Costa","sequence":"additional","affiliation":[{"name":"Instituto Superior Tecnico"}]}],"member":"2796","published-online":{"date-parts":[[2013,9,8]]},"reference":[{"key":"ref0","doi-asserted-by":"crossref","unstructured":"Avila , P. , Montes , M. , and Mir\u00f3 , E. Monolithic Reactors for Environmental Applications a Review on Preparation Technologies Chemical Engineering Journal 109 11 36 2005","DOI":"10.1016\/j.cej.2005.02.025"},{"key":"ref1","doi-asserted-by":"crossref","unstructured":"Meille , V. Review on Methods to Deposit Catalysts on Structured Surfaces Applied Catalysis A: General 315 1 17 2006","DOI":"10.1016\/j.apcata.2006.08.031"},{"key":"ref2","doi-asserted-by":"crossref","unstructured":"Ko\u010d\u00ed , P. , \u0160t\u011bp\u00e1nek , F. , Kub\u00ed\u010dek , M. , and Marek , M. Meso-Scale Modelimg of CO Oxidation in Digitally Reconstructed Porous Pt\/\u03b3-Al 2 O 3 Catalyst Chemical Engineering Science 61 3240 3249 2006","DOI":"10.1016\/j.ces.2005.12.008"},{"key":"ref3","doi-asserted-by":"crossref","unstructured":"Ko\u010d\u00ed , P. , Kub\u00ed\u010dek , M. , and Marek , M. Modeling of Three-Way Catalyst Monolith Converters with Microkinetics and Diffusion in the Washcoat Industrial Engineering Chemistry Research 43 4503 4510 2004","DOI":"10.1021\/ie034137k"},{"key":"ref4","doi-asserted-by":"crossref","unstructured":"Santos , H. , and Costa , M. The Relative Importance of External and Internal Transport Phenomena in Three Way Catalysts International Journal of Heat and Mass Transfer 51 1409 1422 2008","DOI":"10.1016\/j.ijheatmasstransfer.2007.11.005"},{"key":"ref5","doi-asserted-by":"crossref","unstructured":"Zhang , F. , Hayes , R. , and Kolaczkowski , S. A New Technique to Measure the Effective Diffusivity in the Washcoat of a Monolith Reactor Chemical Engineering Research and Design 82 481 489 2004","DOI":"10.1205\/026387604323050191"},{"key":"ref6","doi-asserted-by":"crossref","unstructured":"Hayes , R. , Kolaczkowski , S. , Li , P. , and Awdry , S. Evaluating the Effective Diffusivity of Methane in the Washcoat of a Honeycomb Monolith Applied Catalysis B: Environmental 25 93 104 2000","DOI":"10.1016\/S0926-3373(99)00122-8"},{"key":"ref7","doi-asserted-by":"crossref","unstructured":"Star\u00fd , T. , \u0160olcov\u00e1 , O. , Schneider , P. , and Marek , M. Effective Diffusivities and Pore-transport Characteristics of Washcoated Ceramic Monolith for Automotive Catalytic Converter Chemical Engineering Science 61 5934 5943 2006","DOI":"10.1016\/j.ces.2006.05.014"},{"key":"ref8","doi-asserted-by":"crossref","unstructured":"Kato , S. , Ozeki , H. , Yamada , H. , Tagawa , T. , Takahashi , N. , and Shinjoh , H. Direct Measurements of gas Diffusivity in a Washcoat Layer Under Steady State Conditions at Ambient Temperature Journal of Industrial and Engineering Chemistry 19 3 835 840 2013","DOI":"10.1016\/j.jiec.2012.10.028"},{"key":"ref9","doi-asserted-by":"crossref","unstructured":"Kolaczkowski , S. Measurement of Effective Diffusivity in Catalyst-Coated Monoliths Catalysis Today 83 85 95 2003","DOI":"10.1016\/S0920-5861(03)00218-9"},{"key":"ref10","doi-asserted-by":"crossref","unstructured":"Joshi , S. , Harold , M. , and Balakotaiah , V. Overall Mass Transfer Coefficients and Controlling Regimes in Catalytic Monoliths Chem. Eng. Sci. 65 1729 1747 2010","DOI":"10.1016\/j.ces.2009.11.021"}],"container-title":["SAE International Journal of Engines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/saemobilus.sae.org\/downloads\/articles\/2013-24-0166\/Full%20Text%20PDF","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:13:09Z","timestamp":1760130789000},"score":1,"resource":{"primary":{"URL":"https:\/\/saemobilus.sae.org\/articles\/influence-washcoat-structure-performance-automotive-three-way-catalysts-2013-24-0166"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,9,8]]},"references-count":11,"journal-issue":{"issue":"3"},"URL":"https:\/\/doi.org\/10.4271\/2013-24-0166","relation":{},"ISSN":["1946-3936","1946-3944"],"issn-type":[{"type":"print","value":"1946-3936"},{"type":"electronic","value":"1946-3944"}],"subject":[],"published":{"date-parts":[[2013,9,8]]},"article-number":"2013-24-0166"}}