The present invention provides: a method for producing a shaped product comprising octacalcium phosphate and having a volume of 2.0 mm.sup.3 or more, comprising immersing a precursor ceramic composition containing at least one of Ca and PO.sub.4 in composition, having a solubility in H.sub.2O higher than that of octacalcium phosphate, and having a volume greater than 2.0 mm.sup.3, in a solution containing a component which is not contained in the precursor ceramic composition, among the components Ca, PO.sub.4 and H.sub.2O, which are components of octacalcium phosphate to allow the precursor ceramic composition to react, thereby converting at least a part of the precursor ceramic composition into octacalcium phosphate; and the like.

This disclosure provides for routes of synthesis of acrylic acid and other ,-unsaturated carboxylic acids and their salts, including catalytic methods. For example, there is provided a process for producing an ,-unsaturated carboxylic acid or a salt thereof, the process comprising: (1) contacting in any order, a group 8-11 transition metal precursor, an olefin, carbon dioxide, a diluent, and a metal-treated chemically-modified solid oxide such as a sulfur oxoacid anion-modified solid oxide, a phosphorus oxoacid anion-modified solid oxide, or a halide ion-modified solid oxide, to provide a reaction mixture; and (2) applying reaction conditions to the reaction mixture suitable to produce the ,-unsaturated carboxylic acid or the salt thereof. Methods of regenerating the metal-treated chemically-modified solid oxide are described.

The present disclosure relates to a catalyst for dehydration of glycerin, a preparation method thereof, and a production method of acrolein using the catalyst. Particularly, the catalyst according to an embodiment of the present disclosure is used in a dehydration reaction of glycerin to exhibit high catalytic activity, a high yield, and high selectivity to acrolein and acrylic acid, and has a longer lifetime compared to the conventional catalysts due to a characteristic that coke carbon cannot be easily deposited on the surface of the catalyst.

The present invention relates to a method for preparing a catalyst and a method for preparing unsaturated carboxylic acid using the catalyst prepared according to the preparation method. According to the method for preparing a catalyst, unsaturated carboxylic acid can be provided from an unsaturated aldehyde with a high conversion rate and selectivity.

The present invention relates to a method for preparing a catalyst and a method for preparing unsaturated carboxylic acid using the catalyst prepared according to the preparation method. According to the method for preparing a catalyst, unsaturated carboxylic acid can be provided from an unsaturated aldehyde with a high conversion rate and selectivity.

A process for continuous, on-demand production of dilute acrolein liquid on-site, at or near the point of acrolein injection, by the liquid dehydration of glycerol in an improved tubular reactor where non-aqueous glycerol is combined with a heteropolyacid catalyst, including silicotungstic acid, phosphotungstic acid, or phosphomolybdic acid. The acid catalyst is evenly dissolved and dispersed in the glycerol upstream of the reactor vessel. The reaction is conducted in a tubular reactor which is heated to an elevated reaction temperature. The dilute acrolein produced in the tubular reactor is directed downstream, optionally through a liquid-liquid heat exchanger and then an air-liquid heat exchanger to reduce temperature, and then diluted prior to being injected into sulfide contaminated systems (such as oil & gas water floods, water disposal systems, producing oil wells, and fuel oil storage) via a pressure conduit.

Described herein are solid acid catalysts and the methods for catalytically preparing ,-unsaturated carboxylic acids and/or esters thereof. In one aspect, a zeolite catalyst may be used. The catalyst may, in certain embodiments, be modified to improve the selectivity and/or conversion of a reaction. For instance, a catalyst may be modified by ion exchange to achieve a desirable acidity profile in order to achieve high level of conversion of reactants and selectivity for desirable products of the catalytic reaction. In another aspect, a variety of feed stocks (e.g., starting compositions) may be used including an -hydroxycarboxylic acid, an -hydroxycarboxylic acid ester, a -hydroxycarboxylic acid, a -hydroxycarboxylic acid ester, cyclic esters thereof (e.g., lactide), and combinations thereof.

The present invention relates to a permanently polarized hydroxyapatite and a composition or material comprising thereof. The present invention further relates to a process for obtaining a permanently polarized hydroxyapatite and to different uses of the permanently polarized hydroxyapatite or the composition or material comprising thereof.

The present invention combines the advantages of fabrication of semiconductor heterostructure (Ag.sub.3PO.sub.4WO.sub.3) with plasmonic metals (Pt and Ag) with optical interference to optimize the visible light photo response of plasmonic metals deposited semiconductor (PtAg/Ag.sub.3PO.sub.4WO.sub.3) for visible light assisted H.sub.2 generation utilizing the aqueous bio-alcohols. Crystalline Ag.sub.3PO.sub.4 and WO.sub.3 nanofibers were synthesized by microwave and electrospinning methods. Three different WO.sub.3 nanofibers composition (5, 10 and 15 wt. %) were used to obtain Ag.sub.3PO.sub.4/WO.sub.3 nanocomposite heterostructures, which are effective visible light active photo catalysts. Further, a simple, enviro-friendly, and cost-effective biogenic synthesis method have been achieved using Salvia officinalis extract to decorate Pt and Ag metal nanoparticles on the surface of Ag.sub.3PO.sub.4WO.sub.3 composites. Presence of bioactive agents in the extract are responsible for the Pt and Ag.sub.3PO.sub.4 reduction and for prevention of the Pt nanoparticles from aggregation in aqueous medium.

The present invention combines the advantages of fabrication of semiconductor heterostructure (Ag.sub.3PO.sub.4WO.sub.3) with plasmonic metals (Pt and Ag) with optical interference to optimize the visible light photo response of plasmonic metals deposited semiconductor (PtAg/Ag.sub.3PO.sub.4WO.sub.3) for visible light assisted H.sub.2 generation utilizing the aqueous bio-alcohols. Crystalline Ag.sub.3PO.sub.4 and WO.sub.3 nanofibers were synthesized by microwave and electrospinning methods. Three different WO.sub.3 nanofibers composition (5, 10 and 15 wt. %) were used to obtain Ag.sub.3PO.sub.4/WO.sub.3 nanocomposite heterostructures, which are effective visible light active photo catalysts. Further, a simple, enviro-friendly, and cost-effective biogenic synthesis method have been achieved using Salvia officinalis extract to decorate Pt and Ag metal nanoparticles on the surface of Ag.sub.3PO.sub.4WO.sub.3 composites. Presence of bioactive agents in the extract are responsible for the Pt and Ag.sub.3PO.sub.4 reduction and for prevention of the Pt nanoparticles from aggregation in aqueous medium.