CO2 reforming of ethane using Ni-La intermetallic sites within a nanocapsule framework.

NiLa intermetallic NPs inside a nanoreactor can lower the activation energy of C 2 H 6 and CO 2 , which facilitates the transport/conversion of C 2 *, then significantly improves the dry reforming selectivity of ethane C-C bond breaking over Ni-La@Si catalysts. [Display omitted] • Dry reforming of ethane to syngas is a novel route to co-utilize CO 2 and unconventional gas to get hydrogen energy. • Spatial-chemical bifunctional confinement strategy was offered by Ni-La intermetallic sites within nanocapsule material. • The nanoreactor raised an outstanding catalytic performance in DRE which is the most stable ever reported. • C 2 * is more likely to polymerize than C 1 *, but can be curbed by functional Ni-La nanoreactors. • Physical confinement from the nanocapsule framework plays a more leading role in the anti-coking formation. CO 2 reforming of light alkanes from unconventional gas resources (shale gas/coalbed gas) presents an attractive route to achieve CO 2 utilization and valuable chemical production. However, it remains challenging in both high stability and product selectivity due to the inevitable strong competition between dry reforming and oxidative dehydrogenation pathways. We report here a La modified Ni@SiO 2 nanocapsule as the thermal-catalyst for CO 2 reforming of ethane, achieving complete ethane conversion and remarkable CO 2 conversion of 86.5 %, with stability for more than 200 h experiencing no carbon deposition. Detailed kinetic study, in situ characterizations and DFT calculation results revealed that the formation of NiLa intermetallic sites improved the adsorption of active oxygen species and activation of C 2 H 6 , which stabilized the key intermediate CH 3 CH 2 O* as well as the subsequent C 2 * cracking to CH x (O)*, leading to high selectivity toward syngas. Meanwhile, the removal of carbon deposits on Ni-La 2 O 3 interfaces are faster than Ni surface. The synergism of spatial confinement structure provided by the nanocapsule with sufficient mechanical strength together with the chemical Ni-La 2 O 3 interface of the enwrapped Ni-La mixed metal (oxide) NPs can timely eliminate C 2 * intermediates, which results in the most effective anti-coking ability during ethane reforming. This work highlights a tangible process towards unconventional (C 2+) gas utilization with fine-tunable nanoreactor catalysts. [ABSTRACT FROM AUTHOR]