US 12,442,745 B2
Method for measuring activation energy of catalyst
Xinxin Li, Shanghai (CN); Xinyu Li, Shanghai (CN); Pengcheng Xu, Shanghai (CN); Fanglan Yao, Shanghai (CN); and Li Su, Shanghai (CN)
Assigned to SHANGHAI INSTITUTE OF MICROSYSTEM AND INFORMATION TECHNOLOGY, CHINESE ACADEMY OF SCIENCES, Shanghai (CN)
Appl. No. 18/289,751
Filed by SHANGHAI INSTITUTE OF MICROSYSTEM AND INFORMATION TECHNOLOGY, CHINESE ACADEMY OF SCIENCES, Shanghai (CN)
PCT Filed Dec. 28, 2021, PCT No. PCT/CN2021/141887
§ 371(c)(1), (2) Date Nov. 4, 2024,
PCT Pub. No. WO2022/237192, PCT Pub. Date Nov. 17, 2022.
Claims priority of application No. 202110501613.3 (CN), filed on May 8, 2021.
Prior Publication US 2025/0067649 A1, Feb. 27, 2025
Int. Cl. G01N 5/02 (2006.01); G01N 13/00 (2006.01); G01N 25/00 (2006.01)
CPC G01N 5/02 (2013.01) [G01N 13/00 (2013.01); G01N 25/00 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for measuring activation energy of a catalyst, comprising:
providing an integrated self-heating resonant cantilever;
placing the catalyst in a sampling area of the integrated self-heating resonant cantilever;
providing a probe molecule, and adsorbing the probe molecule with the catalyst;
desorbing the probe molecule from the catalyst by performing programmed heating on the integrated self-heating resonant cantilever, and
obtaining a resonant frequency change-time curve of the integrated self-heating resonant cantilever during the programmed heating,
wherein the obtaining of the resonant frequency change-time curve comprises: obtaining a first preliminary resonant frequency change-time curve by performing a first programmed heating on the integrated self-heating resonant cantilever;
obtaining a second preliminary resonant frequency change-time curve by performing a second programmed heating on the integrated self-heating resonant cantilever; and
obtaining the resonant frequency change-time curve by subtracting the second preliminary resonant frequency change-time curve from the first preliminary resonant frequency change-time curve;
converting the resonant frequency change-time curve into a resonant frequency change-temperature curve by means of a formula T=βt, wherein T represents a temperature of the integrated self-heating resonant cantilever, t represents a heating duration of the programmed heating, and β represents a heating rate of the programmed heating;
converting the resonant frequency change-temperature curve into a coverage-temperature curve by means of a formula

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 wherein θ represents the coverage, Δfm represents a total resonant frequency change during the desorbing of the probe molecule, Δf represents a transient resonant frequency change at a certain time during the desorbing of the probe molecule;
obtaining a coverage change rate-temperature curve by performing first-order differentiation on the coverage-temperature curve, and obtaining Tm and

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 corresponding to local minimum values of the coverage change rate-temperature curve, wherein Tm represents a temperature value where the coverage change rate-temperature curve has a local minimum,

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 represents a coverage change rate where the coverage change rate-temperature curve has a local minimum; and
obtaining a desorption rate constant kd of the catalyst and a desorption activation energy Ed of the catalyst by means of a formula

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 and a formula

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 wherein R represents the gas constant,
wherein adsorbing the probe molecule with the catalyst comprises:
heating the integrated self-heating resonant cantilever in an ammonia gas atmosphere with a flow rate of 50 mL/min to cause the catalyst to adsorb the probe molecule,
performing real-time frequency measurement during adsorption to determine a degree of adsorption, and
completing the adsorption when a catalyst coverage reaches 1, thereby improving accuracy of the measuring of the activation energy of the catalyst.