A catalyst support comprising at least 95% silicon carbide, having surface areas of 10 m.sup.2/g and pore volumes of 1 cc/g. A method of producing a catalyst support, the method including mixing SiC particles of 0.1-20 microns, SiO.sub.2 and carbonaceous materials to form an extrusion, under inert atmospheres, heating the extrusion at temperatures of greater than 1400 C., and removing residual carbon from the heated support under temperatures below 1000 C. A catalyst on a carrier, comprising a carrier support having at least about 95% SiC, with a silver solution impregnated thereon comprising silver oxide, ethylenediamine, oxalic acid, monoethanolamine and cesium hydroxide. A process for oxidation reactions (e.g., for the production of ethylene oxide, or oxidation reactions using propane or methane), or for endothermic reactions (e.g., dehydrogenation of paraffins, of ethyl benzene, or cracking and hydrocracking hydrocarbons).

Disclosed is a method for preparing -carbonyl sulfones. The method comprises: by taking an -carbonyl diazo compound and sodium arylsulfinate as reaction substrates, cheap silver nitrate as an optimal catalyst, 1,10-phenanthroline as a ligand, and potassium persulfate as an oxidant, carrying out coupling reaction in a mixed solvent of acetonitrile and water to obtain a -carbonyl sulfones compound. Compared with the prior art, the method has the following advantages: a wide range of reaction substrates, short reaction time, a relatively high reaction yield, a mild reaction condition, etc. In the present invention, non-toxic and harmless reagents are used as reaction raw materials, so that it has no harm to the environment and satisfies the requirements of contemporary green chemistry development. Post-reaction treatment is relatively simple, and is convenient for separation and purification. In addition, the reaction can achieve gram-scale synthesis, and lays a foundation for actual applications.

Provided herein are methods of generating hindbrain cells, including respiratory hindbrain cells, from pluripotent stem cells. Also provided are methods of generating a three-dimensional organoid comprising a population of hindbrain cells including a heterogeneous population of interneurons.

Disclosed herein is a method for converting ethanol to 1,3-butadiene, wherein the method utilizes H.sub.2 produced during a first step of the method for subsequent conversions involved in the method. In particular aspects, H.sub.2 produced from converting ethanol to acetaldehyde is used to promote the conversion of the acetaldehyde to 1,3-butadiene. The H.sub.2 promotes enhanced catalyst stability, as well as enhanced selectivity and yields of the 1,3-butadiene product. In particular aspects, the method comprises two steps to produce the 1,3-butadiene from the ethanol and H.sub.2 produced from a first step facilitates enhanced selectivities and yields for the second step.

Disclosed herein are aspects of a method for converting an oxygenate feedstock into an olefin-rich product. In some aspects, the method comprises exposing an oxygenate feedstock to a tantalum catalyst composition to form an olefin-rich product. In some aspects, the tantalum catalyst composition comprises tantalum and a support comprising (i) aluminum and/or silicon, and (ii) oxygen.