{"id":2251,"date":"2023-10-19T13:23:38","date_gmt":"2023-10-19T05:23:38","guid":{"rendered":"http:\/\/www3.laiko.net\/all\/why-can-the-molecular-sieve-be-used-as-a-solid-acid-catalyst\/"},"modified":"2023-10-19T13:27:39","modified_gmt":"2023-10-19T05:27:39","slug":"why-can-the-molecular-sieve-be-used-as-a-solid-acid-catalyst","status":"publish","type":"post","link":"https:\/\/www.laiko.net\/fr\/pourquoi-le-tamis-moleculaire-peut-il-etre-utilise-comme-catalyseur-acide-solide\/","title":{"rendered":"Pourquoi le tamis mol\u00e9culaire peut-il \u00eatre utilis\u00e9 comme catalyseur acide solide ?"},"content":{"rendered":"<div class=\"flexbox smcenter other_page richtext\">\n<div class=\"flex-right\">\n<h1>Pourquoi le tamis mol\u00e9culaire peut-il \u00eatre utilis\u00e9 comme catalyseur acide solide ?<\/h1>\n<p><\/p>\n<div class=\"inner_box\">\n<h2>\u2160. Introduction au catalyseur \u00e0 tamis mol\u00e9culaire<\/h2>\n<p><\/p>\n<p>Substance chimique naturelle ou synth\u00e9tique avec une structure en r\u00e9seau. Par exemple, lorsque du dextrane r\u00e9ticul\u00e9 et de la z\u00e9olite sont utilis\u00e9s comme milieu chromatographique, le m\u00e9lange peut \u00eatre fractionn\u00e9 en fonction de la taille mol\u00e9culaire. Les tamis mol\u00e9culaires sont des silicates cristallins ou des aluminosilicates, form\u00e9s de t\u00e9tra\u00e8dres silico-oxyg\u00e8ne ou de t\u00e9tra\u00e8dres alumino-oxyg\u00e8ne reli\u00e9s par des ponts oxyg\u00e8ne pour former un syst\u00e8me de pores et de cavit\u00e9s de taille mol\u00e9culaire de tamis mol\u00e9culaire (g\u00e9n\u00e9ralement 0,3 ~ 2,0 nm). Il a donc les caract\u00e9ristiques de tamiser les mol\u00e9cules. \u00c9galement connu sous le nom de catalyseur z\u00e9olitique, il fait r\u00e9f\u00e9rence \u00e0 un catalyseur avec un tamis mol\u00e9culaire comme composant catalytiquement actif ou l&#039;un des principaux composants actifs. L&#039;utilisation industrielle la plus importante est le catalyseur de craquage par tamis mol\u00e9culaire, qui est un catalyseur acide solide.<\/p>\n<p><\/p>\n<h2>\u2161. Catalyseur acide solide \u00e0 tamis mol\u00e9culaire<\/h2>\n<p><\/p>\n<p>Le tamis mol\u00e9culaire PSA a des performances d&#039;\u00e9change d&#039;ions, des pores de taille mol\u00e9culaire uniforme, une activit\u00e9 catalytique acide et une bonne stabilit\u00e9 thermique et hydrothermique. Il peut \u00eatre transform\u00e9 en catalyseur \u00e0 haute activit\u00e9 et \u00e0 haute s\u00e9lectivit\u00e9 pour de nombreuses r\u00e9actions.<\/p>\n<p><\/p>\n<p>D&#039;une mani\u00e8re g\u00e9n\u00e9rale, un acide solide peut \u00eatre compris comme tout solide capable de changer la couleur d&#039;un indicateur alcalin, ou tout solide capable d&#039;adsorber chimiquement des substances alcalines. Selon la d\u00e9finition de Bronsted et Lewis, un acide solide est un solide capable de produire des protons ou d&#039;accepter des paires d&#039;\u00e9lectrons, tandis que le catalyseur \u00e0 tamis mol\u00e9culaire PSA a une activit\u00e9 catalytique acide. Son acidit\u00e9 provient de la d\u00e9composition des ions ammonium \u00e9chang\u00e9s, de l&#039;\u00e9change d&#039;ions hydrog\u00e8ne ou de l&#039;hydrolyse des cations multivalents contenus lors de la d\u00e9shydratation.<\/p>\n<p><\/p>\n<p>Par exemple:<\/p>\n<p><\/p>\n<p>NH4M\u2500\u2192NH3+HM<\/p>\n<p><\/p>\n<p>H++NaM\u2500\u2192HM+NaCe<\/p>\n<p><\/p>\n<p>3+M+HOMHTCeOIHM+HM<\/p>\n<p><\/p>\n<p>Dans la formule, M repr\u00e9sente le tamis mol\u00e9culaire. Le nombre de centres d&#039;acide protique et la force de l&#039;acide produit sont d&#039;une grande importance pour l&#039;activit\u00e9 catalytique acide des tamis mol\u00e9culaires. La d\u00e9shydratation des deux groupes hydroxyle du tamis mol\u00e9culaire formera un centre acide de Lewis dont la structure est un atome d&#039;aluminium \u00e0 trois coordonn\u00e9es et un atome de silicium charg\u00e9 positivement g\u00e9n\u00e9r\u00e9s en m\u00eame temps. Il existe une opinion selon laquelle l&#039;acide de Lewis est produit \u00e0 partir de l&#039;atome d&#039;aluminium \u00e0 six coordonn\u00e9es form\u00e9 sur le site du cation. La composition du tamis mol\u00e9culaire PSA exprim\u00e9e par le rapport silicium\/aluminium a une grande influence sur son acidit\u00e9 et sa force acide, de sorte que le tamis mol\u00e9culaire peut \u00eatre utilis\u00e9 comme catalyseur acide solide.<\/p>\n<\/p><\/div>\n<div class=\"pro_detail\"><\/div>\n<p><\/p>\n<p class=\"linkh2\">\n<p><\/p>\n<div class=\"more_art_list\"><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"other_page\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Why Can the Molecular Sieve Be Used As a Solid Acid Catalyst? \u2160. Introduction to the molecular sieve catalyst A natural or synthetic chemical substance with a network structure. For example, when cross-linked dextran and zeolite are used as chromatographic medium, the mixture can be fractionated according to molecular size. Molecular sieves are crystalline silicates [&hellip;]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_joinchat":[],"footnotes":""},"categories":[1,54],"tags":[],"class_list":["post-2251","post","type-post","status-publish","format-standard","hentry","category-all","category-blog"],"blocksy_meta":"","featured_image_urls":{"full":"","thumbnail":"","medium":"","medium_large":"","large":"","1536x1536":"","2048x2048":"","trp-custom-language-flag":"","woocommerce_thumbnail":"","woocommerce_single":"","woocommerce_gallery_thumbnail":""},"post_excerpt_stackable":"<p>Why Can the Molecular Sieve Be Used As a Solid Acid Catalyst? \u2160. Introduction to the molecular sieve catalyst A natural or synthetic chemical substance with a network structure. For example, when cross-linked dextran and zeolite are used as chromatographic medium, the mixture can be fractionated according to molecular size. Molecular sieves are crystalline silicates or aluminosilicates, formed by silico-oxygen tetrahedra or alumino-oxygen tetrahedra connected by oxygen bridges to form a pore and cavity system of molecular sieve molecular size (usually 0.3~2.0 nm). So it has the characteristics of sieving molecules. Also known as zeolite catalyst, it refers to a\u2026<\/p>\n","category_list":"<a href=\"https:\/\/www.laiko.net\/fr\/category\/tous\/\" rel=\"category tag\">All<\/a>, <a href=\"https:\/\/www.laiko.net\/fr\/category\/blog\/\" rel=\"category tag\">Blog<\/a>","author_info":{"name":"adminn","url":"https:\/\/www.laiko.net\/fr\/author\/adminn\/"},"comments_num":"0 commentaire","_links":{"self":[{"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/posts\/2251","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/comments?post=2251"}],"version-history":[{"count":1,"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/posts\/2251\/revisions"}],"predecessor-version":[{"id":2448,"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/posts\/2251\/revisions\/2448"}],"wp:attachment":[{"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/media?parent=2251"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/categories?post=2251"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laiko.net\/fr\/wp-json\/wp\/v2\/tags?post=2251"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}