Highly efficient Pd/anodic γ-Al2O3 /Al catalyst coated on replaceable microreactor to enhance the H/D exchange reaction of methane and deuterium

•Isotopic labelling of methane gas with deuterium was investigated into the replaceable microreactor.•The influence of temperature, palladium loading, feed composition and flow rate was investigated.•The obtained results show that the conversion of 95 % of deuterated methane is accessible. Replaceable microreactor, efficiently coated with Pd/anodic γ-Al2O3 catalyst, was investigated to enhance the isotopic labelling of methane with deuterium at atmospheric pressure. The catalyst support was prepared by anodization method. Catalysts with various palladium contents obtained via different concentrations of wet impregnation solution (0.05 M, 0.25 M and 0.0125 M). The influence of temperature (280–400 °C), palladium loading, feed composition of deuterium gas (20–90 %), catalyst type(palladium and ruthenium) and the feed flow rate (GHSV=1000–3000 mL h−1gcat−1) on methane conversion and selectivity of each type of deuterated methanes (CH3D, CH2D2, CHD3, and CD4) was studied. The obtained results showed that the maximum deuterated methane conversion of 95 % happens at 400 °C and GHSV of 1000 mL h−1gcat−1 over Pd1 catalyst in the gas stream containing 90 % deuterium.