5 results about "Temperature-programmed reduction" patented technology

The invention relates to a preparation method of metal beryllium based on a composite reducing agent. The preparation method comprises the following steps: 1) preparing an aluminum oxide coated magnesium composite reducing agent by adopting an in-situ chemical precipitation method; the preparation method comprises the following steps of (1) preparing a composite reducing agent, (2) mixing: mixing the composite reducing agent obtained in the step (1) with beryllium fluoride powder, (3) carrying out temperature programming reduction: carrying out two-stage temperature programming reduction in an inert atmosphere to obtain crude beryllium, (4) carrying out high-temperature vacuum refining, and (5) carrying out densification treatment.The preparation method can synchronously realize a metal beryllium product with the direct recovery rate gt of the beryllium and the purity gt of 82% and the purity gt of 99% on the premise of ensuring safety (no splashing).

The invention relates to the field of heterogeneous catalyst preparation, in particular to a metal-loaded Fischer-Tropsch synthesis catalyst and a preparation method and application thereof. The catalyst comprises an alumina carrier and Co3O4 nanoparticles, wherein the mass ratio of the Co3O4 nanoparticles to the alumina carrier is 1: (3.5-5); the average particle size of the Co3O4 nanoparticles is 8-12 nm, and the difference value between the minimum particle size and the maximum particle size of the Co3O4 nanoparticles is 5-10 nm; in a hydrogen temperature programmed reduction H2-TPR test, the temperature corresponding to the highest value of the first reduction peak of the catalyst is 250-350 DEG C, and the integral area of the reduction peak corresponding to the temperature of 100-400 DEG C accounts for 55-75% of the total integral area of all the reduction peaks. The particle sizes of Co3O4 nanoparticles in the catalyst are intensively distributed in an interval suitable for the Fischer-Tropsch synthesis reaction, and the catalyst has excellent catalytic performance when being used in the Fischer-Tropsch synthesis reaction.

The invention provides a method for characterizing active oxygen species on the surface of a catalyst. The method comprises the following steps: introducing ethylene-oxygen into a catalyst for in-situ pretreatment; carbon monoxide is introduced into the pretreated catalyst for temperature-programmed reduction treatment, and gas and other gas phase products subjected to temperature-programmed reduction treatment are detected. According to the method, the surface oxygen activity and relative quantity of the catalyst are rapidly analyzed, and the reaction activity and selectivity of the catalyst are directly and clearly reflected.

The present application provides a reforming catalyst, a preparation method and application thereof. The catalyst contains a carrier and a reforming active component supported on the carrier. The reforming active component elements include iron and a transition metal. The reduction peak temperature of the surface active metal in the hydrogen temperature programmed reduction test is less than or equal to the reduction peak temperature of a sample with a corresponding active component dispersion of 50%. And / or the active metal is dispersedly distributed on the surface of the carrier. The method comprises: contacting a solution containing a source of the reforming active component with a source of the carrier in equal volumes, the polarity of the solvent in the solution or the weighted polarity in terms of mole fraction is weak polarity, and then drying and calcining. The present application provides a method for dry reforming of ethane and carbon dioxide. The preparation method of the catalyst of the present application controls the polarity of the mixed solvent in the one-step equal-volume co-impregnation, so as to obtain a surface structure with controllable active component distribution. The preparation method of the catalyst of the present application is simple, has little influence on the environment, and is suitable for large-scale production.

The invention discloses a core-shell structure copper-zinc-based methanol reforming catalyst and a preparation method thereof, and belongs to the technical field of catalysts, the catalyst comprises a gallium-doped copper-zinc composite oxide active core and a bifunctional shell layer, the bifunctional shell layer comprises a zinc oxide migration layer and a mesoporous silicon dioxide protection layer which are formed in situ through strong metal-carrier interaction, and the preparation method comprises the steps of preparing a precursor through a coprecipitation method, coating the mesoporous shell layer through an improved Stber method and inducing the SMSI effect through temperature programmed reduction. The catalyst shows excellent catalytic activity and long-term stability in a methanol steam reforming reaction.