5results about How to "Inhibit excessive oxidation" patented technology

This invention discloses the application of a carbon-modified noble metal catalyst in the low-temperature combustion of propane or mixed alkanes. The carbon-modified noble metal catalyst is prepared by adding sodium hydroxide solution dropwise to a cerium salt solution, mixing, and reacting to obtain a cerium dioxide support. The cerium dioxide support is then impregnated in an equal volume of noble metal salt solution, dried, and calcined. The calcined product and glucose are added to deionized water, mixed, and subjected to a hydrothermal reaction, followed by drying and calcination to obtain the final product. In this invention, carbon species exist in the form of doping or interstitial filling, inducing lattice distortion and a high concentration of surface oxygen vacancies in the support, significantly improving the mobility of lattice oxygen and the reactivity. Simultaneously, the interfacial carbon species optimize the microelectronic environment of the active center through strong electron interactions, maintaining the low valence state of Ru and the metallic states of Pt and Pd. This catalyst effectively avoids the shielding effect of the carbon layer and exhibits excellent catalytic combustion activity and stability for propane and mixed alkanes at low temperatures.

The invention discloses a nitrogen-doped ruthenium oxide loaded graphene electrocatalyst and a preparation method and application thereof, and belongs to the technical field of electrocatalysts.The preparation method comprises the steps that a nitrogen source, a ruthenium source and graphene are added into water, stirred and freeze-dried, and a precursor is obtained; and heating the precursor to 450-700 DEG C in an air atmosphere, and annealing to obtain the nitrogen-doped ruthenium oxide loaded graphene electrocatalyst. Ruthenium oxide particles are loaded on the surface of graphene, nitrogen is introduced at the same time, nano-sheet-loaded evenly-distributed small nano-particles are obtained, the specific surface area is large, more active sites are exposed, the atomic structure is further adjusted and optimized through introduction of the nitrogen, excessive oxidation of ruthenium oxide at an anode is inhibited, and the electrochemical performance of the anode is improved. Therefore, the electrocatalytic oxygen evolution performance and stability of ruthenium oxide are greatly improved.

The invention relates to a system and method for preparing ketone through hydrogen peroxide mediated alkane conversion and application. The system comprises a two-step electrocatalytic reaction tank and a one-step thermocatalytic fixed bed reaction tank. The electro-catalytic reaction tank is composed of a zero-gap membrane electrode tank and an improved flow electrochemical tank, hydrogen and oxygen are generated by the electro-catalytic reaction tank through water electrolysis, and then the hydrogen and the oxygen are respectively introduced into the electro-catalytic reaction tank for oxidation reduction to prepare hydrogen peroxide; generated hydrogen peroxide is directly mixed with alkane gas through a tee joint and then enters a thermocatalytic fixed bed reactor, and a ketone product can be prepared. Compared with the prior art, the method has excellent ketone selectivity and production efficiency, and is a more efficient and stable reaction system compared with the currently reported electro-catalysis or thermocatalysis technology.

This invention relates to a method for enhancing the stirring intensity during vanadium extraction, belonging to the field of steel pretreatment. The method includes the following three steps: first, vanadium-containing molten iron is added to a converter; then, a top-and-bottom blowing process is used for smelting; coolant is added according to the composition and temperature at the smelting endpoint; finally, semi-steel is removed from the lance at the smelting endpoint. The top-blown gas is an oxygen-nitrogen mixture, and the total flow rate of the oxygen-nitrogen mixture is 31,000~35,000 Nm³. 3 / h; the oxygen consumption per ton of iron, the top blowing lance position, and the nitrogen consumption per ton of iron are controlled in segments according to the blowing period; the bottom blowing gas is nitrogen, and the nitrogen supply intensity is controlled in segments according to the blowing period. This invention significantly enhances the stirring intensity of the molten pool without significantly increasing the temperature rise rate through the synergistic effect of the high-flow-rate oxygen-nitrogen mixed gas from the top and the variable-flow-rate nitrogen from the bottom, thereby shortening the mixing time and enhancing the slag-metal reaction, further increasing the vanadium oxidation amount and further reducing the TFe content in the vanadium slag.

The application of binaphthyl Salen cobalt molecular catalyst modified BiVO4 photoanode belongs to the field of photoelectrocatalysis technology and organic synthesis cross. BiOI film is deposited on FTO conductive glass by electrochemical deposition method, and then is converted into BiVO4 photoanode substrate by calcination; 3-hydroxy substituted binaphthyl Salen cobalt molecular catalyst CoL is synthesized; CoL is loaded on the surface of BiVO4 by cyclic voltammetry electrodeposition to obtain a hybrid photoanode. The photoanode is applied to the photoelectrocatalytic olefin epoxidation reaction, water is used as oxygen source, and acetone-water is used as electrolyte. The strong interface coupling between the catalyst and BiVO4 is strengthened by the electrodeposition of the molecular catalyst strategy, and the interface charge transport efficiency, reaction conversion rate and selectivity are improved. The conversion rate of styrene reaches 99%, the selectivity of epoxide reaches more than 90%, and the stability is excellent. The application provides a new way for green and efficient synthesis of epoxide, and has wide application prospect.