Terrestrial geothermal fields and oceanic hydrothermal vents are considered as candidate environments for the emergence of life on Earth. Nevertheless, the ionic strength and salinity of oceans present serious limitations for the self-assembly of amphiphiles, a process that is fundamental for the formation of first protocells. Consequently, we systematically characterized the efficiency of amphiphile assembly, and vesicular stability, in terrestrial geothermal environments, both, under simulated laboratory conditions and in hot spring water samples (collected from Ladakh, India, an Astrobiologically relevant site). Combinations of prebiotically pertinent fatty acids and their derivatives were evaluated for the formation of vesicles in aforesaid scenarios. Additionally, the stability of these vesicles was characterized over multiple dehydration-rehydration cycles, at elevated temperatures. Among the combinations that were tested, mixtures of fatty acid and its glycerol derivatives were found to be the most robust, also resulting in vesicles in all of the hot spring waters that were tested. Importantly, these vesicles were stable at high temperatures, and this fatty acid system retained its vesicle forming propensity, even after multiple cycles of dehydration-rehydration. The remaining systems, however, formed vesicles only in bicine buffer. Our results suggest that certain prebiotic compartments would have had a selective advantage in terrestrial geothermal niches. Significantly, our study highlights the importance of validating results that are obtained under ‘buffered’ laboratory conditions, by verifying their plausibility in prebiotically analogous environments.

Gallium–platinum promoted HZSM-5 is found to be a promising catalyst for ethane aromatization reaction. The influence of Pt as a promoter on the activity of Ga/HZSM-5 catalyst for ethane aromatization has been investigated. Comparative study was performed between bimetallic Ga–Pt based and Mo based HZSM-5, where the GaPt/HZSM-5 showed better aromatic and hydrogen selectivity. Pt promoted Ga/HZSM-5 catalyst exhibited higher activity compared to pure Ga/HZSM-5 catalyst. The presence of platinum in the gallium zeolite considerably accelerated dehydrogenation step in ethane aromatization. In addition, GaPt/HSZM-5 deactivated significantly slower than Mo/HZSM-5 and Ga/HZSM-5. TPO study of spent catalysts revealed that carbonaceous deposit on GaPt/HZSM-5 catalyst was burnt off at lower temperature compared to pure Ga/HZSM-5 catalyst, indicating the presence of Pt facilitated hydrogen spillover resulting in hydrogenolysis of coke precursors. The reaction mechanism associated with aromatic formation is postulated based on the correlation between catalytic performance and surface characterization.

Facile synthesis of ultrasmall gold nanoclusters of size <2 nm dispersible in water using a novel quaternary ammonium ligand is reported. Further, arrays of these nanoclusters are encapsulated in monodisperse silica nanospheres of size 25–30 nm. The photophysical characteristics of the clusters are found to be intact upon encapsulation, rendering the resulting composite material ideal for fluorescence imaging applications. We have further shown the utilization of these materials in catalysis as precursors for Au nanoparticles encapsulated in porous silica.

Catalytic shale gas decomposition for tunable tip/base grown CNTs and CO2-free H2.