Recent Patents on Catalysis (v.2, #2)

TiO2 Supported Photobiocatalytic Systems by Victor Nadtochenko, Vitaliy Nikandrov, Yanina Borisova, Galina Nizova, Arseny Aybush, Andrei Kostrov, Igor Shagadeev, Eugeniy Lukashov, Fedor Gostev, Ivan Shelaev, Mamadou Traore, Andrei Kanaev, Vladimir Shuvalov, Aleksei Semenov (91-100).
We report on a performance of the photocatalytic solar energy convertors based on mesoporous TiO2 films withimmobilized enzymes and membrane pigment-protein complexes of bacterial reaction centers Rhodobacter sphaeroidesand Synechocystis sp. PCC 6803 photosystem-I (PS I) using our patented immobilization technique. These semiconductor-enzymes-pigment-protein systems functioned as both the light-harvester and charge separator in photocatalytic and solarcells self-assembled on nanostructured semiconductors. We described our recent patents on different possibilities ofelectrons photogeneration in the TiO2 conduction band (c.b.) as well as possibilities to use the potential of e- in the TiO2c.b for the catalytic reduction of H+ to molecular hydrogen and for reduction of NAD+ (NADP+) to NADH(NADPH) byimmobilized enzymes. We also report on femtosecond dynamics of charge separation in PS I with relation to these photocatalyticsolar energy convertors.

In this review, recent developments in fine chemicals synthesis, catalysis, microreactor design and applicationsare discussed. Specifically, new advances in continuous micro process engineering, packed-bed devices and photoreactorsare discussed to include recent patents in these areas. In addition, new energy sources including ultrasounds and microwavesintegrated into microstructured reactors are also discussed. Novel progress in materials to build these devices suchas single walled nanotubes are discussed with respect to their properties and synthesis. This approach foresees developmentsin the use of nanomaterials in microreactor design and the impact these will have in the synthesis and purificationof different fine chemicals in continuous flow devices.

Patents on Photocatalyst Incorporated Cement Based Materials by Mert M. Oymak, Deniz Uner (116-129).
This patent survey emphasizes applications of photocatalyst incorporated cement based materials. The patentsfrom two companies, i.e., Italcementi and Toto Ltd., were emphasized in the manuscript due to their greater number ofpatents. The product survey reflected the current commercial photocatalysis market. Construction sector applicationsdominated the patents and products.

Isomerization of p-diisopropylbenzene (p-DIPB) to m-diisopropylbenzene (m-DIPB) was carried out usingmetal modified Hβ zeolites at high temperature and in the absence of a solvent. The metal cations used for the modificationof Hβ were typical Lewis acidic cations Fe3+, Al3+, Ti4+, Sn4+ and Sb3+. The modified zeolite catalysts were heated at120oC, and calcined at 280oC, and 550oC. They were characterized by XRD, FE-SEM, HR-TEM, FT-IR, N2-desorption(BET), NH3-TPD, Pyridine-IR and TGA techniques for structural, morphological, acidity and stability investigation. Particlesize of the crystallites was determined by HR-TEM analysis and the size was in the range of 15-35 nm. At 250oC, Al-Hβ, Fe-Hβ and Ti-Hβ showed 68-75% conversion of p-DIPB and 42-54% selectivity towards m-DIPB. The calcinationtemperature had no effect on the activity. Isomerization increases with increased acidity. Thus, metal modified Hβ catalystsare excellent, efficient, and alternative heterogeneous catalysts for the isomerization of p-diisopropylbenzene (p-DIPB) to m-diisopropylbenzene (m-DIPB). This process is a greener alternative for the classical AlCl3 process as discussedin the article along with the relevant patents.

Photocatalysis is an important process used in the decomposition of chemical residues, which are mostly xenobioticspresent in contaminated water. The hydroxyl radical technology using a semiconductor with low energy UV lightsource has the advantage of oxidation and decomposition process when compared to other conventional techniques resultingin the decomposition of toxic chemicals to non toxic CO2 and water. The early patents on the use of photolysis andphoto catalysts go back to 1930 where hydrogen peroxide was used in the presence of direct sun light. Subsequently, introductionof metal catalysts played a role in enhancing the decomposition process of chemicals at industrial level. Thethrust for the maximum utilization of solar energy and the introduction of several nano catalysts during the past decadehas led to the development of several designs that automate the process of decontamination of pesticide residues at industriallevel. Apart from the sunlight, UV and IR, the addition of sonication, heating and flow through systems have addedadditional advantages to the decomposition technique. The new methods patented have facilitated the decontamination ofresidues of pesticides which are insecticides, herbicides, fungicides acaricides etc in broad category or the so called xenobioticsfrom the aquifers, surfaces of fruits and vegetables a boost to the food industry. The cleaning or decomposingprocess takes place in the aqueous phase with the aid of formation of hydroxyl / oxygen free radicals and in the presenceof transition metal catalysts which are mostly metal oxides and semiconductors. The TiO2 catalyst, in different forms,from micro to nano and coated / doped are extensively used in several of these processes due to its easy excitation underdirect sunlight / UV light facilitating the transfer of photon energy to the molecule to breakdown into small and non toxicfragments.

Patent Selections: (148-152).