Oxidative steam reforming of ethanol (OSRE) to produce hydrogen has been investigated over a series of supported PtRu catalysts, with different supports. Bimetallic PtRu-based catalysts were prepared by the impregnation method using H2PtCl6 and RuCl3 as precursors. Six supports (reducible oxides of ZrO2, CeO2, and Co3O4, and irreducible oxides of ZnO, Al2O3, and NiO) were chosen to fabricate bimetallic catalysts. The catalytic performance of the OSRE reaction in the series of PtRu-based samples was evaluated using a fixed-bed flow reactor under atmospheric pressure. In front reaction, the catalyst was pre-activated by reduction under 200°C for 3 h. The gas hourly space velocity was adjusted at 66,000 h−1, and the optimal molar ratios of the H2O/EtOH and O2/EtOH feeds were 4.9 and 0.44, respectively. The results indicated that the PtRu supported on the ZrO2 and CeO2 exhibited superior catalytic performance in the OSRE reaction under a low temperature (a TR of approximately 320°C) for producing the main products of H2 and CO2 with lower CO and CH4 by-products. Also, it was quite stable during a long time evaluation; the maximum YH2 maintained at 4.5–4.2, and the CO distribution approached 3.3–3.5 mol% around 84 h test at 340°C over the PtRu/ZrO2 catalyst.
In this study, a nanostructured zinc oxide/reduced graphene oxide (ZnO/rGO) composite was deposited on a quartz crystal microbalance (QCM) as a toluene gas sensor at room temperature. A series of ZnO, rGO and ZnO/rGO sensing materials was fabricated and characterized by X-ray diffraction
(XRD), scanning electron microscope (SEM), and Raman spectroscopy. There was significant efficiency of the ZnO/rGO composite on the sensing performance for toluene. For specific gas fluxes, the nanostructured ZnO/rGO offered sufficient paths and region for vapor diffusion and adsorption. The
sensing test results illustrated that the nanostructured ZnO/rGO composite showed significant enhancement in the frequency shifts (△f) for toluene comparing to pure ZnO and rGO. Also, the ZnO/rGO-coated QCM sensor displayed a fast response (both the response and recovery times < 30
s) and reproducibility for sensing toluene gas at room temperature. We believe that the novel insights on ambient temperature gas sensing on nanostructured ZnO/rGO composite could provide a new strategy for preparing a highly efficient sensing materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.