5 results about "Topological transformation" patented technology

The invention discloses a catalyst for preparing methanol through high-temperature CO2 hydrogenation as well as a preparation method and application of the catalyst. The active component of the catalyst is a Mn-doped ZnZrO2 solid solution, and the catalyst is prepared by adopting a crystal growth regulation and control-in-situ topological conversion method: by taking an amphiphilic block copolymer or CTAB (Cetyltrimethyl Ammonium Bromide) as a template, inducing directional crystallization of a precursor through solvothermal to construct a hierarchical porous structure; topological transformation is realized through staged heat treatment, so that the Mn element is uniformly doped in the crystal lattice of the catalyst in an atomic scale; the surface of the catalyst is reconstructed through oxidation and reduction treatment, and the oxygen vacancy density and the acid-base property distribution are accurately regulated and controlled. Experimental results show that the CO2 conversion rate of the catalyst is gt at the high temperature of 280-350 DEG C; the methanol selectivity is gt; the space-time yield reaches more than 700 mg / (gcat.h <-1 >), and the performance is reduced by 1t after 200 hours of operation; 3%. The key problems that the catalyst is easy to sinter at high temperature, the active site distribution is uneven, the methanol selectivity is low and the like are effectively solved, and a high-performance and stable catalyst system is provided for efficient resource utilization of CO2.

The application adopts a co-precipitation method to prepare a NiZr / CoOx catalyst prepared by topological transformation of a layered double hydroxide (LDHs) precursor and a method for catalytic hydrogenation of biomass-derived compounds. The catalyst used is a NiZrCo catalyst prepared by a co-precipitation method. The method used is: adding unsaturated biomass-derived compounds into a reaction container containing a solvent, using isopropyl alcohol as a solvent and a hydrogen source, and realizing the hydrogenation reaction of aldehyde ketone compounds under the action of the NiZr / CoOx catalyst. In order to improve the catalytic activity of Co species in the hydrogenation reaction, Ni and Zr are doped in the cobalt salt to obtain the catalyst. The addition of Zr not only helps the dispersion of Ni and Co, but also provides acid sites for the catalytic system, the strong electronic interaction between metal species improves the catalytic activity, and the existence of oxygen vacancies provides adsorption sites for C=O in furfural, greatly improving the catalytic performance. The method for preparing the NiZr / CoOx catalyst doped with Ni, Zr and Co is simple, the process is easy to operate, the obtained catalyst has high activity, and exhibits good catalytic performance in the catalytic hydrogenation reaction of biomass-derived compounds. The catalyst has magnetism, and is convenient for recycling. In addition, the method uses an in-situ hydrogenation method to replace the traditional external hydrogen to provide a hydrogen source, and has high safety.

The invention discloses an LDO catalyst for an efficient CO2 methanation reaction and a preparation method thereof.The preparation method comprises the following steps that NiAlLDH of a hydrotalcite structure serves as a precursor, in-situ topological transformation is conducted in the hydrogen reducing atmosphere, and the LDO catalyst for the efficient CO2 methanation reaction is obtained. Meanwhile, full-spectrum response and a good photothermal effect are achieved.

The invention discloses a zither performance video content intelligent analysis and retrieval system, and belongs to the technical field of video content analysis and retrieval, the system comprises a multi-modal feature extraction module, a manifold topology transformation module, a semantic scene analysis module and a self-adaptive retrieval module, deep fusion of visual and audio features is realized through manifold topology transformation, and the video content is analyzed and retrieved. A topological structure is established based on Riemannian metrics, and precise recognition and time sequence segmentation of scenes such as technique display, track playing and teaching explanation are achieved. The adaptive retrieval module constructs a closed-loop feedback mechanism, dynamically adjusts feature extraction weights and measurement parameters according to retrieval confidence, and realizes continuous optimization of system performance, the problems of insufficient multi-modal information fusion, inaccurate scene recognition, low retrieval efficiency and the like in the prior art are solved, the scene recognition accuracy is improved by more than 12%, and the system performance is improved by more than 12%. And the retrieval precision is improved by more than 30%.

This invention discloses a catalyst for high-temperature CO2 hydrogenation to methanol, its preparation method, and its applications. The active component of the catalyst is a Mn-doped ZnZrO2 solid solution, prepared using a "crystal growth regulation-in-situ topological transformation" method: using amphiphilic block copolymers or CTAB as templates, a hierarchical porous structure is constructed through solvothermal-induced directional crystallization of the precursor; a topological transformation is achieved through staged heat treatment, resulting in atomically uniform Mn doping in the catalyst lattice; further oxidation and reduction treatments promote catalyst surface reconstruction, precisely controlling the oxygen vacancy density and acid-base distribution. Experimental results show that at high temperatures of 280–350 °C, the catalyst achieves a CO2 conversion rate >26.5%, a methanol selectivity >78%, and a space-time yield of 700 mg / (g). cat ·h ‑1 The performance degradation is less than 3% after 200 hours of operation. This invention effectively overcomes key challenges such as easy sintering of catalysts at high temperatures, uneven distribution of active sites, and low methanol selectivity, providing a high-performance and stable catalyst system for the efficient resource utilization of CO2.