Plasma-based CO conversion has attracted increasing interest. However, to understand the impact of plasma operation on post-plasma processes, we studied the effect of adding N, N/CH and N/CH/HO to a CO gliding arc plasmatron (GAP) to obtain valuable insights into their impact on exhaust stream composition and temperature, which will serve as feed gas and heat for post-plasma catalysis (PPC). Adding N improves the CO conversion from 4 % to 13 %, and CH addition further promotes it to 44 %, and even to 61 % at lower gas flow rate (6 L/min), allowing a higher yield of CO and hydrogen for PPC.
View Article and Find Full Text PDFThe hydrolysis of the phosphonate ester linker during the synthesis of hybrid (organic-inorganic) TiO nanoparticles is important when forming porous hybrid organic-inorganic metal phosphonates. In the present work, a method was utilized to control the in-situ partial hydrolysis of diphosphonate ester in the presence of a titania precursor as a function of acid content, and its impact on the hybrid nanoparticles was assessed. Organodiphosphonate esters, and more specific, their hydrolysis degree during the formation of hybrid organic-inorganic metal oxide nanoparticles, are relatively under explored as linkers.
View Article and Find Full Text PDFWhile synthesis-properties-performance correlations are being studied for organophosphonic acid grafted TiO , their stability and the impact of the exposure conditions on possible changes in the interfacial surface chemistry remain unexplored. Here, the impact of different ageing conditions on the evolution of the surface properties of propyl- and 3-aminopropylphosphonic acid grafted mesoporous TiO over a period of 2 years is reported, using solid-state P and C NMR, ToF-SIMS and EPR as main techniques. In humid conditions under ambient light exposure, PA grafted TiO surfaces initiate and facilitate photo-induced oxidative reactions, resulting in the formation of phosphate species and degradation of the grafted organic group with a loss of carbon content ranging from 40 to 60 wt %.
View Article and Find Full Text PDFTwo new alkaline earth metal-organic frameworks (AE-MOFs) containing Sr(II) () or Ba(II) () cations and extended tetrahedral linker (MTA) were synthesized and characterized in detail (UPJS stands for University of Pavol Jozef Safarik). Single-crystal X-ray analysis (SC-XRD) revealed that the materials are isostructural and, in their frameworks, one-dimensional channels are present with the size of ~11 × 10 Å. The activation process of the compounds was studied by the combination of in situ heating infrared spectroscopy (IR), thermal analysis (TA) and in situ high-energy powder X-ray diffraction (HE-PXRD), which confirmed the stability of compounds after desolvation.
View Article and Find Full Text PDFModification of metal oxides with organophosphonic acids (PAs) provides the ability to control and tailor the surface properties. The metal oxide phosphonic acid bond (M-O-P) is known to be stable under harsh conditions, making PAs a promising candidate for the recovery of metals from complex acidic leachates. The thiol functional group is an excellent regenerable scavenging group for these applications.
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