Role of metal oxides in chemical evolution

Prebiotic studies on the interaction of zirconia nanoparticles and ribose nucleotides and their role in chemical evolution

International Journal of Astrobiology ◽

10.1017/s1473550421000033 ◽

2021 ◽

Vol 20 (2) ◽

pp. 142-149

Author(s):

Avnish Kumar Arora ◽

Pankaj Kumar

Keyword(s):

Electron Microscopy ◽

Metal Oxide ◽

Metal Oxides ◽

Chemical Evolution ◽

Ribonucleic Acid ◽

Zirconium Oxide ◽

Origins Of Life ◽

Neutral Ph ◽

Interaction Studies

AbstractStudies on the interaction of biomolecules with inorganic compounds, mainly mineral surfaces, are of great concern in identifying their role in chemical evolution and origins of life. Metal oxides are the major constituents of earth and earth-like planets. Hence, studies on the interaction of biomolecules with these minerals are the point of concern for the study of the emergence of life on different planets. Zirconium oxide is one of the metal oxides present in earth's crust as it is a part of several types of rocks found in sandy areas such as beaches and riverbeds, e.g. pebbles of baddeleyite. Different metal oxides have been studied for their role in chemical evolution but no studies have been reported about the role of zirconium oxide in chemical evolution and origins of life. Therefore, studies were carried out on the interaction of ribonucleic acid constituents, 5′-CMP (cytidine monophosphate), 5′-UMP (uridine monophosphate), 5′-GMP (guanosine monophosphate) and 5′-AMP (adenosine monophosphate), with zirconium oxide. Synthesized zirconium oxide particles were characterized by using vibrating sample magnetometer, X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy. Zirconia particles were in the nanometre range, from 14 to 27 nm. The interaction of zirconium oxide with ribonucleic acid constituents was performed in the concentration range of 5 × 10−5–300 × 10−5 M. Interaction studies were carried out in three mediums; acidic (pH 4.0), neutral (pH 7.0) and basic (pH 9.0). At neutral pH, maximum interaction was observed. The interaction of zirconium oxide with 5′-UMP was 49.45% and with 5′-CMP 67.98%, while with others it was in between. Interaction studies were Langmurian in nature. Xm and KL values were calculated. Infrared spectral studies of ribonucleotides, metal oxide and ribonucleotide–metal oxide adducts were carried out to find out the interactive sites. It was observed that the nitrogen base and phosphate moiety of ribonucleotides interact with the positive charge surface of metal oxide. SEM was also carried out to study the adsorption. The results of the present study favour the important role of zirconium oxide in concentrating the organic molecules from their dilute aqueous solutions in primeval seas.

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Role of Metal Oxides in Chemical Evolution: Interaction of Ribose Nucleotides with Alumina

Astrobiology ◽

10.1089/ast.2007.0143 ◽

2009 ◽

Vol 9 (2) ◽

pp. 165-171 ◽

Cited By ~ 18

Author(s):

Avnish Kumar Arora

Keyword(s):

Metal Oxides ◽

Chemical Evolution

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Single and Dual Metal Oxides as Promising Supports for Carbon Monoxide Removal from an Actual Syngas: The Crucial Role of Support on the Selectivity of the Au–Cu System

Catalysts ◽

10.3390/catal9100852 ◽

2019 ◽

Vol 9 (10) ◽

pp. 852 ◽

Cited By ~ 5

Author(s):

Bernay Cifuentes ◽

Felipe Bustamante ◽

Martha Cobo

Keyword(s):

Metal Oxides ◽

High Surface ◽

High Surface Area ◽

Carbon Deposits ◽

Promising Strategy ◽

Cu Catalysts ◽

Dual Metal ◽

Effect Of The Support ◽

Lower Capacity

A catalytic screening was performed to determine the effect of the support on the performance of an Au–Cu based system for the removal of CO from an actual syngas. First, a syngas was obtained from reforming of ethanol. Then, the reformer outlet was connected to a second reactor, where Au–Cu catalysts supported on several single and dual metal oxides (i.e., CeO2, SiO2, ZrO2, Al2O3, La2O3, Fe2O3, CeO2-SiO2, CeO2-ZrO2, and CeO2-Al2O3) were evaluated. AuCu/CeO2 was the most active catalyst due to an elevated oxygen mobility over the surface, promoting CO2 formation from adsorption of C–O* and OH− intermediates on Au0 and CuO species. However, its lower capacity to release the surface oxygen contributes to the generation of stable carbon deposits, which lead to its rapid deactivation. On the other hand, AuCu/CeO2-SiO2 was more stable due to its high surface area and lower formation of formate and carbonate intermediates, mitigating carbon deposits. Therefore, use of dual supports could be a promising strategy to overcome the low stability of AuCu/CeO2. The results of this research are a contribution to integrated production and purification of H2 in a compact system.

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