Metallic Sn spheres and SnO2@C core-shells by anaerobic and aerobic catalytic ethanol and CO oxidation reactions over SnO2 nanoparticles

Abstract

SnO2 has been studied intensely for applications to sensors, Li-ion batteries and solar cells. Despite this, comparatively little attention has been paid to the changes in morphology and crystal phase that occur on the metal oxide surface during chemical reactions. This paper reports anaerobic and aerobic ethanol and CO oxidation reactions over SnO2 nanoparticles (NPs), as well as the subsequent changes in the nature of the NPs. Uniform SnO2@C core-shells (10 nm) were formed by an aerobic ethanol oxidation reaction over SnO2 NPs. On the other hand, metallic Sn spheres were produced by an anaerobic ethanol oxidation reaction at 450 °C, which is significantly lower than that (1200 °C) used in industrial Sn production. Anaerobic and aerobic CO oxidation reactions were also examined. The novelty of the methods for the production of metallic Sn and SnO2@C core-shells including other anaerobic and aerobic reactions will contribute significantly to Sn and SnO2-based applications.

Metallic indium spheres by the anaerobic ethanol oxidation of indium oxide

“…This suggests that the In oxide becomes less active, possibly due to a change in the crystal structure. Based on the reaction products and the literature [25,26], the following plausible mechanism is proposed. after anaerobic ethanol oxidation [25].…”

“…Based on the reaction products and the literature [25,26], the following plausible mechanism is proposed. after anaerobic ethanol oxidation [25]. The anaerobic ethanol oxidation over Ga 2 O 3 powder was also tested, but no metallic Ga (a melting point of approximately 30 ºC) was obtained and the crystal structure did not change.…”

“…Because the melting point of In metal is ~156 °C[14] and much lower than the reaction temperature of 600°C, the reduced In melted to form a droplet at high temperatures. As the sample temperature was lowered, the liquid In M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 13 droplets changed to metallic In spheres[25]. For a metal with a low melting point,Kim et al.…”

Trimodally porous SnO2 nanospheres with three-dimensional interconnectivity and size tunability: a one-pot synthetic route and potential application as an extremely sensitive ethanol detector

“…In addition, for all sensing temperatures, the 3M-SnO 2 -based sensor exhibits a high selectivity for ethanol, with low cross-responses to other interference gases, such as formaldehyde, ammonia, carbon monoxide, hydrogen, benzene, toluene and xylene (Supplementary Figure S11). The selective detection of ethanol in SnO 2 gas sensor is well known, 37 which can be explained by high catalytic activity of SnO 2 for ethanol oxidation 38 as well as high reactivity of ethanol compared with other gases, such as aldehydes, aromatics and ketones. 39 This offers excellent gas-sensing characteristics for monitoring drunk driving.…”

Synthesis of Co-doped SnO2 nanofibers and their enhanced gas-sensing properties

“…The result revealed that the sensor based on S3 nanofibers showed the highest response to 100 ppm ethanol and the value was about 4 times higher than that of pure SnO 2 . The selective detection of ethanol in SnO 2 gas sensor had been mentioned by Yoon's work [34], which can be explained by high catalytic activity of SnO 2 for ethanol oxidation as well as high reactivity of ethanol compared with other gases, such as aldehydes, aromatics and ketones [35][36][37].…”