Data on tuning phase crystal of boron-doped manganese oxide and activation in removal of formaldehyde

Abstract

The data in this work provides the effect of aging temperature on manganese oxide allotropes prepared by hydrothermal method in the presence of boron dopant. The synthesized samples were labeled as B/Mn_xO_y -100, B/Mn_xO_y -150, and B/Mn_xO_y -180 corresponding to the hydrothermal temperature at 100, 150, and 180 °C, respectively. X-ray diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS) methods were conducted to clarify the crystalline structure, as well as the amount of potassium, manganese, and boron elements in the three synthesized samples. Major cryptomelane crystal was achieved at 100 °C of aging temperature for B/Mn_xO_y -100 sample. Pyrolusite which was detected as impurity phase over B/Mn_xO_y -150 powder was characterized as main crystalline phase for B/Mn_xO_y -180 sample. ICP-MS analysis proved an absence of potassium element only for the B/Mn_xO_y -180 sample being in comprised of a push of potassium cations out the tunnel system of cryptomelane structure. Furthermore, scanning electron microscope (SEM) images evidenced noticeably morphological change from cryptomelane nanorods (for B/Mn_xO_y -100) to pyrolusite slabs (for B/Mn_xO_y -180) while increasing the aging hydrothermal condition from 100 to 180 °C. Size distribution diagrams were defined with the assistance of ImageJ and were plotted in Origin software. The diameter of nanorods were 14.8 ± 0.3 nm for B/Mn_xO_y -100 and 17.2 ± 0.4 nm for B/Mn_xO_y -150 while that was 100.3 ± 2.5 nm for B/Mn_xO_y -180 sample indicating an aggregation of nanorods into slabs at 180 °C of aging temperature. Formaldehyde conversion data were collected and computed with a gas chromatograph flame ionization detector (GC-FID) instrument. The B/Mn_xO_y -180 material deteriorated into formaldehyde degradation at 80 °C of oxidation reaction temperature suggesting an inactivated pyrolusite phase for catalytic oxidation. The formaldehyde removal efficiency over the B/Mn_xO_y -100 material reached 28.4 ± 1.2 % and 36.9 ± 0.9 % at 80 and 100 °C, respectively offering an active cryptomelane-phase of B/Mn_xO_y -100 for formaldehyde abatement at low reaction temperature. Altogether, the current data provided valuable insights into the influence of aging temperature on the crystalline of manganese oxide-based materials and a feasibly catalytic performance of B/Mn_xO_y -100 cryptomelane in formaldehyde elimination.

Keywords: B/OMS-2; Formaldehyde oxidation; Hydrothermal method; Pyrolusite.