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Isomorphic substitution of Rh at varying levels on the B site of lanthanum zirconate pyrochlore (La 2 Zr 2 O 7 ; designated LZ) resulted in the formation of thermally stable catalysts suitable for fuel reforming reactions operating at 900°C. Three specific catalysts are reported here: (a) unsubstituted lanthanum zirconate (LZ), (b) LZ with 2 wt% substituted Rh (L2RhZ), and (c) LZ with 5 wt% substituted Rh (L5RhZ). These catalysts were characterized by XRD, XPS, and H 2-TPR. XRD of the fresh, calcined catalysts showed the formation of the pyrochlore phase (La 2 Zr 2 O 7) in all three materials. In L5RhZ, the relatively high level of Rh substitution led to the formation of LaRhO 3 perovskite phase which was not observed in the L2RhZ and LZ pyrochlores. TPR results show that the L5RhZ consumed 1.57 mg H 2 /g cat , which is much greater than the 0.508 H 2 /g cat and 0.155 mg H 2 /g cat for L2RhZ and LZ, respectively, suggesting that the reducibility of the pyrochlore structure increases with increasing Rh-substitution. DRM was studied on these three catalysts at three different temperatures of 550, 575, and 600°C. The results showed that CH 4 and CO 2 conversion was significantly greater for L5RhZ compared to L2RhZ and no activity was observed for LZ, suggesting that the surface Rh sites are required for the DRM reaction. Temperature programmed surface reaction showed that L5RhZ had light-off temperature 80°C lower than L2RhZ. The spent catalysts after runs at each temperature were characterized by temperature programmed oxidation (TPO) followed by temperature programmed reduction and XRD. The TPO results showed that the amount of carbon formed over L5RhZ is almost half of that formed on L2RhZ.

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Although deep eutectic solvents (DESs) have attracted significant interest in various separation processes, rational methods guiding task-specific DES selection are still scarce. In this work, a systematic method for screening DESs as sustainable separation solvents is proposed and exemplified by the CO 2 capture application. To achieve a large screening space, experimentally reported DESs are collected exhaustively from literature; for the most studied choline chloride (ChCl) based DESs a correlation between their freezing point depression and COSMO-RS molecular descriptors of their hydrogen bond donors (HBDs) is established, which is applied to search a huge number of novel combinations of ChCl and HBD candidates for potential DESs. From the extended database combining experimental and potential DESs, promising CO 2 absorbents are screened by integrating (a) the freezing point constraint according to the operating requirement, (b) the estimation of environment, health, and safety (EHS) impacts using quantitative structure-activity relationships methods, and (c) the prediction of thermodynamic properties by COSMO-RS. The practical solvent performance of the top DES candidates is finally studied by experiments, identifying ChCl: ethylenecyanohydrin (at mole ratios of 1:2 and 1:3) as very attractive CO 2 absorbents.

A novel surface-enhanced Raman scattering (SERS) sensing system which operates by the self-assembly of Ag nanoparticles (AgNPs) onto the nanocomposite of AgNPs and graphene oxide (AgNP-GO) in the presence of two complementary DNAs has been developed. In this system, AgNP-GO serves as a SERS-active substrate. The AgNPs with the modification of non-fluorescent 4-mercaptobenzoic acid (4-MBA) act as highly efficient Raman probes for DNA hybridization. When probe DNAs on AgNP-GO are complementary to target DNAs on AgNPs functionalized with 4-MBA, the DNA hybridization occurring directs the self-assembly of AgNPs onto AgNP-GO, leading to the creation of SERS hot spots. Due to the fact that partial 4-MBA molecules are located in the region of the hot spots, their SERS signals are greatly enhanced, indicating successful DNA hybridization. It is noteworthy that the size of AgNPs contributes significantly to the enhancement of SERS activity. The detection limit of the target DNAs at the pM level can be achieved through the self-assembly of large sized AgNPs onto AgNP-GO. More importantly, the AgNP-AgNP-GO system shows reproducible SERS signals in proportion to the logarithm of the target DNA concentrations spanning from 10(-6) to 10(-12) M and the excellent capability for multiplex DNA detection.