Abstract:
Mesoporous graphitic carbon nitride (MGCN) materials and method of making said MGCN materials is described. The MGCN materials include a three dimensional cyanamide based carbon nitride matrix having tunable pore diameters, a pore volume between 0.40 and 0.80 cm 3 g -1 , and a surface area of 195 to 300 m 2 gm -1 . The matrix comprises sheets of three dimensionally arranged s-heptazine (tri- s-triazine) units. The MGCN materials are used as catalysts in aldol condenstation reactions, in particular Knoevenagel reactions. The mesoporous structure is obtained by means of a silica template like KIT-6, which is removed after polymerisation of the cyanamide monomers.
Abstract:
Es wird ein partikuläres Material sowie ein Verfahren zu seiner Herstellung bereit gesteilt, das zeolithische Partikel mit kristallinem Aufbau umfasst, die als Hauptkomponente ein Zeolithmaterial mit einer aus Si, O und gegebenenfalls AI gebildeten zeolithischen Gerüststruktur und/oder ein zeolithähnliches Material mit einer zeolithischen Gerüststruktur, die nicht nur aus Si, O und gegebenenfalls AI gebildet ist, enthalten, wobei die zeolithischen Partikel als im Wesentlichen sphärische Partikel mit Nanometerdimensionen vorliegen.
Abstract:
The invention discloses a method of making a mesoporous material with hexagonaily arranged mesopores comprising the following steps: a) dissolving a surfactant in water to form a surfactant solution; b) adding an acid to the surfactant solution to form a mixture having pH less than 2; c) adding a silica precursor to said mixture to form a precipitate; d) aging the precipitate; e) filtering, washing and drying the aged precipitate of step d) and subjecting said precipitate to calcination. An alternative method of making the mesoporous material is also disclosed. The mesoporous material is suitable for supporting a catalyst. Furthermore, the invention describes a supported metal catalyst incorporating such a mesoporous material.
Abstract:
The water tolerant heterogeneous acid catalyst (ICaT-2) has been disclosed herein. The catalyst of the invention comprises of rare earth metals in the form of trifluromethansulphonate anchored with hexagonal organic-inorganic functionalized mesoporous silica as base metal through organic-inorganic linkages i.e. via mercapto-groups or sulphonate groups. The said catalyst composition has the specific surface area in the range of 200 m2/g to 850 m /g and the pore diameter in the range of 20-50 A. The ICaT-2 catalyst was found to be highly active and reusable for biomass based chemicals.
Abstract:
This invention related to method of producing 5-ydroxymethyl furfural from fructose by using heterogeneous solid acid catalyst ICaT-2 without giving any considerable byproduct. This process is very economical as it involved high yield and simple separation process for product. Reactions are carried out by using the mixture of solvent system in batch reactor. The process is tolerance towards high fructose loading. The simplification in work-up, separation of product and very good recyclability of the catalyst make the process cost-effective, sustainable and efficient for industrial utilization. Isolation procedure for 5-hydroxymethyl furfural is also discussed. ICaT-2 is prepared by a co-condensation sol-gel route. Hexadecyl amine was dissolved in ethanol and water mixture. Mixture of tetraethyl orthosilicate and 3- (mercaptopropyl)trimethoxysilane were added to the above solution. It is treated with lanthanum chloride (400 mg) for 2 h. The slurry was filtered and treated with trifluromethanesulfonic acid (5.4 mmol) at 30 °C for 2 h. The slurry was filtered and washed with water and dried under vacuum to get the active ICaT-2 catalyst.
Abstract:
La présente invention concerne un procédé de préparation d'un matériau poreux structuré comportant une charpente inorganique structurée composée de murs à base d'oxyde métallique dans lesquels des nanoparticules de métal 0 sont incorporées, comprenant les étapes suivantes : a) disposer d'une suspension de nanoparticules hydrophiles de métal 0 stabilisées par des ligands non échangeables conférant leur caractère hydrophile aux nanoparticules, b) faire croître la charpente inorganique à partir d'un précurseur inorganique, autour des nanoparticules de métal 0 stabilisées par les ligands hydrophiles non échangeables, en présence d'un agent porogène, c) éliminer l'agent porogène et au moins partiellement les ligands non échangeables conférant leur caractère hydrophile aux nanoparticules.
Abstract:
É descrito um processo catalítico à base de peneiras moleculares para reações de esterificação em presenca de um catalisador básico da família M41S e fazer reagir sob condições de transesterificação e em presenca de uma quantidade eficaz do dito catalisador um álcool e um éster, mantendo as condições reacionais durante o período de tempo necessário para ocorrer a reação, separar o catalisador sólido do meio reacional, para utilização em um novo ciclo reacional e recuperar os produtos da reação com rendimentos superiores aqueles obtidos em reações desse tipo em presenca de catalisadores do estado da técnica ou em ausencia de catalisadores. Exemplos desses catalisadores são as peneiras moleculares [CTA]-Si-MCM-41, [CTA]-Si- MCM-48 ou [CTA]-Si-MCM-50.
Abstract:
L' invention a trait à un procédé de préparation d'un copolymère dibloc comprenant un bloc hydrophile (B) et un bloc hydrophobe (A), ou d'un copolymère tribloc comprenant un bloc hydrophile (B), un bloc hydrophobe (A) et un second bloc hydrophobe (A' ), ledit procédé comprenant les étapes suivantes : a) une étape d'addition 1,2 sur un groupe terminal éthylénique, ou deux groupes terminaux éthyléniques, d'un polymère hydrophile, d'une alcoxyamine répondant à la formule (I) suivante : dans laquelle : * R 1 et R 3 , identiques ou différents, représentent un groupe alkyle, linéaire ou ramifié, ayant un nombre d'atomes de carbone allant de 1 à 3; * R 2 représente un atome d'hydrogène, un métal alcalin, tel que Li, Na, K, un ion ammonium tel que NH 4 +, NBu 4 +, NHBu 3 +, un groupe alkyle, linéaire ou ramifié, ayant un nombre d'atomes de carbone allant de 1 à 8, un groupe phényle; b) une étape de mise en contact avec le milieu issu de l'étape a) d'un ou plusieurs monomères précurseurs d'un bloc hydrophobe pendant un temps suffisant pour obtenir le copolymère dibloc bloc hydrophile (B) - b -bloc hydrophobe (A) dans le cas où l'étape d'addition a) s'est produite sur un seul groupe terminal éthylénique du polymère hydrophile; ou pour obtenir le copolymère tribloc bloc hydrophile (A) -b-bloc hydrophile (B) -b-second bloc hydrophobe (A' ) dans le cas où l'étape d'addition a) s'est produite sur deux groupes terminaux éthyléniques du polymère hydrophile. Utilisation des copolymères obtenus en tant qu'agents structurants de matériaux mésoporeux, tels que la silice présentant des tailles de pores supérieures à 15 nm.
Abstract:
This invention relates to a method for making shaped bodies having a silica content of at least 85 wt%, to shaped bodies made by such method, to catalyst compositions comprising shaped bodies made by such methods and to catalytic conversion processes using catalyst compositions comprising shaped bodies made by such methods. The method of making the shaped bodies comprises the steps of a) forming shaped bodies from a mixture obtained from at least one amorphous silica powder, at least one silica sol having a pH below 7, and at least one polymeric organic extrusion aid, optionally supplemental liquid medium and optionally crystallites of a zeolite or zeolite-type material; b) drying the shaped bodies obtained in step a); and c) heating the shaped bodies to a temperature ranging from about 500 o C to about 800 o C.