Research On H₂S Gas Chemical Sensing Mechanism Based On Resonant Micro-cantilever And Performance Evaluation Of Solid Acid-base Catalysts

In this paper,we use the resonant micro-cantilever as the carrier,and the detection condition is in the atmospheric pressure gas atmosphere.The chemical sensing mechanism of the resonant dual-cantilever H₂S gas sensor is studied.We explored the application of the micro-cantilever as a scientific instrument in the field of materials science is explored.By analyzing the surface interface force between acidic molecular sieve and NH3,extracting kinetic/thermodynamic parameters to achieve the catalytic activity evaluation of molecular sieve,selecting the most efficient catalyst,and guiding the catalyst activity to be further optimized.The specific content includes the following four parts:First,the introduction of the MEMES resonant micro-cantilever sensor.This section includes the development status of resonant cantilever beams at home and abroad,the sensing mechanism,the latest application trends,and existing problems.Second,the chemical sensing mechanism of the double cantilever H₂S sensor that can identify trace detection.In this study,we use a lab-designed double cantilever structure.One end of one cantilever beam was loaded with a nitrogen-doped porous carbon material that has a trace detection function for H₂S,and the other cantilever end was loaded with a basic formula for the H₂S recognition function.The copper carbonate compound has a detection limit of 1 ppb for H₂S gas and can identify H₂S gas from seven different interference gases.This unique dual cantilever sensor improves sensitivity and selectivity.Material Studio simulates the adsorption process of H₂S gas by nitrogen-doped porous carbon,analyzes the chemical sensing mechanism thoroughly,calculates the adsorption enthalpy change value,and verifies the recoverability of nitrogen-doped porous carbon as a chemical sensing material.Third,the catalytic activity of solid acid-base catalysts.The application of solid acid-base catalysts in the industry is of great importance.The current research on catalyst performance is still in the qualitative stage,and the process is cumbersome.Therefore,an efficient and time-saving,data-based model is needed to characterize and analyze it.In this study,NH3 gas adsorption experiments were performed on four classical molecular sieves,and the enthalpy change of adsorption was calculated.The catalytic activity of the four fundamental catalysts was quantitatively compared for the first time.The subsequent infrared diffuse reflection experiments also verified the reliability of the test results.Fourth,summary and outlook.The resonant double cantilever H₂S sensor studied in this thesis has achieved a breakthrough in its sensitivity and selectivity,which can be used for gas leak monitoring.The detection limit can reach lppb.At the same time,the sensor can identify H₂S gas from 7 interfering gases.However,the irreversibility reaction between the basic copper carbonate and H₂S gas,there is a limit to the life of the sensor.For the quantitative characterization of molecular sieve catalysts,we only studied the catalytic activity of the catalyst by enthalpy change.Furthermore,the properties of solid acid-base catalysts need further studies,Such as ?S????whether a chemical reaction occurs between solid acid-base catalysts and NH3??G???,?Indicating the direction in which the solid acid-base catalyst reacts with NH3?,K????the degree of reaction between the solid acid-base catalyst and NH3?,????the number of active sites in the solid acid-base catalyst?,N?the Total number of sites?and that.