Active Site-Directed Tandem Catalysis on Single Platinum Nanoparticles for Efficient and Stable Oxidation of Formaldehyde at Room Temperature

Abstract

The application of tandem catalysis is rarely investigated in degrading organic pollutants in the environment. Herein, a tandem catalyst on single platinum (Pt) nanoparticles (Pt0 NPs) is prepared for the sequential degradation of formaldehyde (HCHO) to carbon dioxide gas [CO2(g)] at room temperature. The synthesis approach includes coating of uniform Pt NPs on SrBi2Ta2O9 platelets using a photoreduction process, followed by calcination of the sample in the atmosphere to tune partial transformation of Pt0 atoms to Pt2+ ions in the tandem catalyst. The conversion of HCHO to CO2(g) is monitored by in situ Fourier transform infrared spectroscopy, which shows first conversion of HCHO to CO3 2– ions onto Pt0 active sites and subsequently the conversion of CO3 2– ions to CO2(g) by neighboring Pt2+ species of the catalyst. The later process with Pt2+ species does not allow CO3 2– poisoning of the catalyst. The enhanced activity of the prepared tandem catalyst to oxidize HCHO is maintained continuously for 680 min. Comparatively, the catalyst without Pt2+ shows activity for only 40 min. Additionally, the tandem catalyst presented herein performs better than the Pt/titanium dioxide (TiO2) catalyst to degrade HCHO. Overall, the tandem catalyst may be applied to degrade organic pollutants efficiently.

Advances and Fundamental Understanding of Electrocatalytic Methane Oxidation

“…Significant modifications to increase the intrinsic activity of EMO catalyst through bifunctional single metal‐metal oxides; electronic, curvature, roughness, defects, and geometric effects have not yet been found. Notably, a well‐designed tandem scheme has emerged as a promising strategy for promoting high activity and selectivity to C n products in other catalytic conversions inspiring its feasibility for electrocatalytic methane conversion [82–86] …”

MOF-enabled confinement and related effects for chemical catalyst presentation and utilization

“…395,396 An obvious virtue of this approach is that short-lived intermediates can be captured by proximal second-or third-step catalysts and converted to desired products. While a single active-site can sometimes catalyse successive reactions, 397 often two or more active sites are required. 398 We will highlight recent work in which proximally confining or siting complementary active-sites within MOFs leads to superior, tandem catalytic activity.…”

Single-atom site catalysts for environmental catalysis

“…Thus, methods of eliminating HCHO are vital for the environment and human health, and catalytic oxidation of HCHO is an efficient and promising approach to solve these issues. Note that the majority of studies have currently focused on K [136], Na [57], Ag [49], Au [137] and Pt [138][139][140] based SACs for HCHO catalytic oxidation.…”