Synthesis of Pt doped Mg-Al layered double oxide/graphene oxide hybrid as novel NOx storage-reduction catalyst

We report the synthesis of Pt doped Mg-Al layered double oxide/graphene oxide (Pt-LDO/GO) hybrid as novel NOx storage and reduction (NSR) catalyst. For the preparation of layered double hydroxide/GO hybrids, LDHs and graphite oxide were first exfoliated into single-layers, followed by self-assembly. LDO/GO hybrids were obtained by thermal treatment of LDH/GO. The obtained LDH/GO and LDO/GO hybrids were thoroughly characterized using XRD, SEM, TEM, FT-IR, and BET analyses. Then the NOx storage capacity of neat LDO and LDO(10)/GO hybrids were compared by isothermal NOx adsorption tests. The influence of adsorption temperature, gas flow, calcination temperature, and LDH dispersion concentration were systematically studied. The results demonstrated that the NOx storage capacity of neat LDO was significantly improved from 0.175 to 0.314 mmol g (1) by introducing only 7 wt% of GO, which could be attributed to the enhanced particle dispersion and stabilization. Moreover, the NOx storage capacity of the hybrid could be further increased close to 0.335 mmol g(-1) catalyst by doping with 2 wt% Pt. The Pt-LDO(1)/GO also exhibited excellent lean-rich cycling performance, with an overall 71.7% of NOx removal. This work provided a new scheme for the preparation of highly dispersed LDH/GO hybrid type NSR catalyst.