3 results about "No conversion" patented technology

The invention provides a zeolite-based catalyst and a preparation method thereof. According to the catalyst, flaky ZSM-5 zeolite is taken as a carrier, and a composite material with a synergistic catalysis effect is formed by loading bimetallic active components of Cu and Fe step by step. The NO conversion rate and N2 selectivity of the catalyst in the temperature range of 250-400 DEG C are both kept at 95% or above, and the catalyst has the advantages of being high in low-temperature activity, high in wide-temperature-range applicability, good in hydrothermal stability and excellent in poisoning resistance. The preparation method comprises seed crystal induction-hydrothermal crystallization synthesis of flaky ZSM-5 zeolite and a step-by-step metal loading process of Cu ion exchange and Fe dipping-evaporation-calcination, and the process is simple, convenient and controllable and is suitable for industrial application.

This invention relates to a diesel oxidation catalyst that enhances NO oxidation capacity, its preparation method, and its application. The diesel oxidation catalyst comprises layered and regionalized coatings A, B, C, and optionally D. Based on the weight content of precious metals per unit volume, the sum of the loadings of platinum and palladium, the active components of precious metals, in coating B is greater than or equal to the sum of the loadings of platinum and palladium, the active components of precious metals, in coating A, and the sum of the loadings of platinum and palladium, the active components of precious metals, in coating C is greater than the sum of the loadings of platinum and palladium, the active components of precious metals, in coating B. This structural design significantly improves the low-temperature NO conversion capacity. The inclusion of coating C ensures stable fuel ignition performance, while coating D regulates the exhaust gas flow field. This catalyst has a simple preparation process, excellent performance, and can achieve a high NO conversion rate while meeting fuel ignition requirements under low precious metal loading conditions, making it suitable for industrial production applications.

The invention relates to the technical field of denitration catalytic materials, and discloses a preparation method of a denitration catalytic material special for emission of a methanol internal combustion engine, and the preparation method comprises the following steps: S1, preparing a multi-element synergistic precursor mixed solution: sequentially mixing a carrier precursor, an active metal salt, a main ligand, a double-dynamic auxiliary ligand and a coordination regulator to obtain the multi-element synergistic precursor mixed solution; adjusting the pH value, and stirring to obtain a transparent and uniform multi-element synergistic precursor mixed solution; s2, gradient coordination polymerization reaction: putting the multi-element synergistic precursor mixed solution into a closed high-pressure reaction kettle, and reacting by adopting a stepped heating polymerization process to obtain an integrated gel product; s3, doping gas assisted low-temperature plasma activation; and S4, surface acid-base modification post-treatment. Through the synergistic effect of the double-dynamic auxiliary ligand and the coordination regulator, the gradient coordination polymerization process is matched to regulate and control the precursor structure, the reaction induction period is shortened, the NO conversion rate in the low-temperature interval is increased, and the problem that the low-temperature exhaust denitration reaction speed of the methanol internal combustion engine is low is solved.