A photocatalytic device includes a substrate having a surface, and an array of conductive projections supported by the substrate and extending outward from the surface of the substrate. Each conductive projection of the array of conductive projections has a semiconductor composition. The semiconductor composition establishes a photochemical diode. The surface may be nonplanar such that subsets of the array of conductive projections are oriented at different angles.

A cobalt catalyst and a preparation method thereof are provided. The cobalt catalyst includes a carrier and a catalytically active substance; the carrier is a cobalt-based substrate material; the catalytically active substance is grown on the surface of the carrier, and the catalytically active substance has a morphology of hydrangea-shaped nanospheres. The cobalt catalyst is an autogenously grown monolithic nanosphere catalyst with a three-dimensional structure assembled by nano-sheets on the catalyst surface. The cobalt catalyst has a high specific surface area and can fully expose the catalytically active sites to enhance the catalytic efficiency. Compared to a nanowire catalyst, the cobalt catalyst has better self-supporting properties, and the active components are not easily aggregated nor fall off during a use process. Therefore, the cobalt catalyst has a longer service life.

Catalyst systems are provided, along with corresponding methods, for single stage conversion of synthesis gas to fuel boiling range products with increased selectivity for either naphtha production (C.sub.5-C.sub.9) or distillate production (C.sub.10-C.sub.20). The increased selectivity for naphtha production or distillate production is provided in conjunction with a reduced selectivity for higher boiling range components (C.sub.21+).

Catalyst systems are provided, along with corresponding methods, for single stage conversion of synthesis gas to fuel boiling range products with increased selectivity for either naphtha production (C.sub.5-C.sub.9) or distillate production (C.sub.10-C.sub.20). The increased selectivity for naphtha production or distillate production is provided in conjunction with a reduced selectivity for higher boiling range components (C.sub.21+).

A method is disclosed for rejuvenation a cobalt Fischer Tropsch catalyst used in a Fischer Tropsch process operating in recycle mode. The method permits the use of specific inert gases to adjust the mole weight of the gas so that the recycle compressor designed for normal steady state operation can also be used in the method. Hydrogen from a membrane permeate stream is added to the reactor loop at a temperature between 300 F and 400 F and the carbon oxides are reacted out to purify the hydrogen. This stream is continuously recycled and the temperature is raised to between 425 F and 500 F and held at the final temperature for between 4 hours and 48 hours. The cobalt Fischer Tropsch catalyst is effectively rejuvenated in-situ by the method.

A method is disclosed for rejuvenation a cobalt Fischer Tropsch catalyst used in a Fischer Tropsch process operating in recycle mode. The method permits the use of specific inert gases to adjust the mole weight of the gas so that the recycle compressor designed for normal steady state operation can also be used in the method. Hydrogen from a membrane permeate stream is added to the reactor loop at a temperature between 300 F and 400 F and the carbon oxides are reacted out to purify the hydrogen. This stream is continuously recycled and the temperature is raised to between 425 F and 500 F and held at the final temperature for between 4 hours and 48 hours. The cobalt Fischer Tropsch catalyst is effectively rejuvenated in-situ by the method.

The present invention relates to a process for preparing a cobalt-containing Fischer-Tropsch synthesis catalyst with good physical properties and high cobalt loading. In one aspect, the present invention provides a process for preparing a supported cobalt-containing Fischer-Tropsch synthesis catalyst, said process comprising the following steps of: (a) impregnating a support powder or granulate with a cobalt-containing compound; (b) calcining the impregnated support powder or granulate and extruding to form an extrudate; or extruding the impregnated support powder or granulate to form an extrudate and calcining the extrudate; and (c) impregnating the calcined product with a cobalt-containing compound; or forming a powder or granulate of the calcined product, impregnating with a cobalt-containing compound and extruding to form an extrudate.

The present invention relates to a process for preparing a cobalt-containing Fischer-Tropsch synthesis catalyst with good physical properties and high cobalt loading. In one aspect, the present invention provides a process for preparing a supported cobalt-containing Fischer-Tropsch synthesis catalyst, said process comprising the following steps of: (a) impregnating a support powder or granulate with a cobalt-containing compound; (b) calcining the impregnated support powder or granulate and extruding to form an extrudate; or extruding the impregnated support powder or granulate to form an extrudate and calcining the extrudate; and (c) impregnating the calcined product with a cobalt-containing compound; or forming a powder or granulate of the calcined product, impregnating with a cobalt-containing compound and extruding to form an extrudate.

A process for preparing a catalyst comprises coating substantial internal surfaces of porous inorganic powders with titanium oxide to form titanium oxide-coated inorganic powders. After the coating, an extrudate comprising the titanium oxide-coated inorganic powders is formed and calcined to form a catalyst support. Then, the catalyst support is impregnated with a solution containing one or more salts of metal selected from the group consisting of molybdenum, cobalt, and nickel.

There is provided a catalyst that enables the production of isobutylene with a high selectivity in the production of isobutylene by dehydration of isobutanol. The catalyst according to the present invention contains at least one metal selected from Group 6 to Group 14 metal elements in Period 4 to Period 6 of the periodic table, in alumina which includes alumina consisting of one or more crystal phases of a monoclinic crystal phase, a tetragonal crystal phase, and a cubic crystal phase.