Pt/Ni single-atom alloy boosts mechano-pyrolysis of alkane into hydrogen

Mechanochemistry approach was utilized to solve the carbon deposition during alkane pyrolysis process. Pt/Ni single-atom alloy (SAA) was constructed on Ni balls surface as catalyst and grinding medium simultaneously, and physical collision of metallic balls generated mechanical energy to remove the deposited carbon and accelerate reaction rates. XANES spectra proved Pt/Ni SAA structure on the Ni ball surface, and its turnover frequency (TOF) was 1530 h−1 under 1 atm and 450 °C without by-products. An extremely long lifetime of methane pyrolysis at least 350 h on stream has been obtained. This Pt/Ni SAA was also active for mechano-pyrolysis of ethane/propane, and DFT calculations confirmed that the improvement of catalytic efficiency originated from the d-band center up-shifting under mechanic stress on Pt/Ni SAA surface. This mechanical catalysis study provides an alternative route for clean hydrogen production and a strategy for deposited carbon removal under mechanical conditions. [Display omitted] •Pt/Ni single atom alloy achieves 350 h CH4 pyrolysis without deactivation.•Mechanical energy doubled CH4 conversion compared with that under static mode.•The d-band center up-shifting under mechanic stress boosts the CH* cleavage.•The mechanical energy removes the deposited carbon powder on active sites.•The presence of mechanical energy enabled CH4 pyrolysis since 260 °C.