A method includes at least two-stage process for the oligomerization of short-chain olefins in the presence of a catalyst, wherein the regeneration of the catalyst is stage-customized.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Articles comprising a catalyst film comprising VOx, MoO.sub.3 or WO.sub.3, and TiO.sub.2 deposited on a substrate are disclosed. The articles are useful for selective catalytic reduction (SCR) of NOx in exhaust gases. Methods for producing such articles deposit a catalyst film on the substrate to form a coated substrate, which is then calcined. When used in an SCR process, the coated articles have enhanced activity for NOx conversion, reduced activity for SOx conversion, or both. Light-weight, coated articles having high catalyst loads can be fabricated at the same or reduced dimensions when compared with laminated articles, and increased kNOx/kSOx ratios are available even from coated articles having relatively thin catalyst films. The articles should have particular value for power plant operations, where coal and high-sulfur fuels are commonly used and controlling sulfur trioxide generation is critical.

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.

A method for recovering a catalyst, wherein a solution containing a reaction mixture obtained by performing a hydrogenation reaction in a presence of a catalyst containing a platinum group metal is brought into contact with a fiber membrane having a group containing an amino group or a thiol group on a surface, thereby recovering the platinum group metal included in the solution is provided.

A method for recovering a catalyst, wherein a solution containing a reaction mixture obtained by performing a hydrogenation reaction in a presence of a catalyst containing a platinum group metal is brought into contact with a fiber membrane having a group containing an amino group or a thiol group on a surface, thereby recovering the platinum group metal included in the solution is provided.

Methods for regenerating a spent catalyst are disclosed. Such methods may employ a step of chlorinating the spent catalyst in the gas phase, followed by decoking the chlorinated spent catalyst, and then fluorinating the de-coked catalyst in a fluorine-containing solution of a fluorine-containing compound.

Methods for regenerating a spent catalyst are disclosed. Such methods may employ a step of chlorinating the spent catalyst in the gas phase, followed by decoking the chlorinated spent catalyst, and then fluorinating the de-coked catalyst in a fluorine-containing solution of a fluorine-containing compound.