Quantitative determination of the content of palladium deposited on kieselguhr using hydrogen isotherms

•A method to determine Pd content in Pd/K composite was developed depending on hydrogen isotherms.•In the hydride β-phase of Pd-H(D), relationship between pressure and hydrogen content in Pd strictly follows Langmuir equation.•Monolayer absorption capacity derived from Langmuir equation was used to calculate the Pd content.•Particle size of palladium and cycle of absorption/desorption was considered to ensure the testing accuracy.