Milling corundum nanoparticles High-purity (α-Al 2 O 3 ) could enable applications such as more stable catalyst supports or precursors for high-strength ceramics. of only produces micrometer-scale particles, and direct synthesis from other aluminum oxides that would be likely starting materials, γ-Al , fails because the high activation barrier converting lattice structure these cubic close-packed oxides. Amrute et al. show ball milling boehmite, γ-AlOOH, created ∼13-nanometer-diameter purity...

Cuprous delafossites exhibit exceptional electrical, magnetic, optical, and catalytic properties. Through the application of a battery in situ ex characterization methods complemented by density functional theory (DFT) calculations, we gathered an in-depth understanding synthesis CuMO2 (M = Al, Cr, Fe, Ga, Mn) solid-state reaction Cu2O M2O3 their stability against oxidative disproportionation to CuM2O4 CuO. TGA-DTA XRD studies revealed that nature M3+ cation strongly impacts (i) formation...

Rationally designed RuO2-based Deacon catalysts can contribute to massive energy saving compared the current electrolysis process in chemically recycling HCl produce molecular chlorine. Here, we report on our integrated approach between state-of-the-art experiments and calculations. The aim is understand industrial catalyst its realistic surface state derive mechanistic insights into this sustainable reaction. We show that practically relevant RuO2/SnO2 consists of two major RuO2...

Deacon process revisited: A shaped RuO2/SnO2–Al2O3 catalyst was designed for highly active and stable performance in HCl oxidation to Cl2. In addition its binding effect, alumina acts as a stabilizer prevent sintering, endowing the with extraordinary longevity. Pilot tests give solid prospects industrial implementation of this catalytic system. Detailed facts importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset....

With time comes wisdom: Since the implementation of CuCl2 for HCl oxidation by Deacon in 1868, search stable copper catalysts has been futile. Cuprous delafossite, CuCrO2 (see picture), is shown to have unprecedented stability against chlorination, allowing durable Cl2 production with no metal loss. Based on this, a highly active CuCrO2-CeO2 composite was developed, cost-effective recovery method. As service our authors and readers, this journal provides supporting information supplied...

The gas-phase oxidation of HCl to Cl2 over heterogeneous catalysts, known as the Deacon process, is a sustainable way for chlorine recycling in chemical industry. Mechanistic aspects this reaction metal oxides (Cr2O3, CeO2, and MnO2) have been gathered using temporal analysis products (TAP) reactor compared with outcome previous studies RuO2 CuO. intrinsic features TAP technique enable investigation demanding safe manner under highly controlled conditions. We correlated catalytic activity...

The use of in situ approaches to study mechanisms experimentally demanding and complex reactions under conditions practical relevance opens doorways discover new or improved heterogeneous catalysts. A representative example within this category is the gas-phase oxidation HCl Cl2 (Deacon process). Studies temporal analysis products (TAP) reactor complemented by flow experiments at ambient pressure evidenced pronounced mechanistic differences between copper catalysts (CuO, CuCl, CuCl2, that...

IrO2 has been investigated as alternative rutile-type catalyst to RuO2 for gas-phase HCl oxidation. The conversion level over at 723 K was comparable that of ca. 170 lower temperature, in line with the higher computed energy barrier chlorine evolution former oxide. Similarly RuO2, chlorination took place only surface, which is predicted exhibit full occupation coordinatively unsaturated iridium sites and replacement 50% oxygen bridge positions by chlorine. Advantageously, more resistant than...

The catalytic oxyhalogenation is an attractive route for the functionalization of methane in a single step. This study investigates oxychlorination (MOC) and oxybromination (MOB) under wide range conditions over various materials having different oxidation properties to assess effect hydrogen halide (HX, X = Cl, Br) on catalyst performance. activity catalysts, ranked as RuO2 > Cu–K–La–X CeO2 VPO TiO2 FePO4, correlated with their ability oxidize gas-phase reactivity halogen methane. product...

Nanocrystalline corundum synthesized by ball milling of boehmite is found to be exceptionally robust toward chemical weathering, a common problem transition aluminas in different applications, most notably the case supported catalysts, which are exposed hydrothermal reaction environments. Detailed characterization and surface cation coordination analysis indicate that absence tetrahedral Al species on makes it stable weathering. A cobalt catalyst developed using nano-α-Al2O3 as support...

CeO(2) has been identified as an efficient catalyst for HCl oxidation in the temperature range of 623-723 K provided that oxygen content feed mixture was sufficiently high to avoid bulk chlorination and thus deactivation. Here we characterise ceria its fresh post-reaction states by adsorption CO(2), NH(3) CO. Micro-calorimetry, FTIR TPD experiments are complemented DFT calculations, which assess energies vibrational frequencies. The calculations were performed on lowest energy surface,...

A copper catalyst based on a delafossite precursor (CuAlO(2)) displays high activity and extraordinary lifetime in the gas-phase oxidation of HCl to Cl(2), representing cost-effective alternative RuO(2)-based catalysts for chlorine recycling.

The gas-phase HCl oxidation was studied over bulk and supported Cr2O3-based catalysts by means of kinetic experiments in a fixed-bed reactor at ambient pressure variable temperature, inlet O2/HCl ratio, contact time. Cr2O3 exhibited high activity for Cl2 production. X-ray diffraction the used detected no phase change. Temperature-programmed reduction with hydrogen photoelectron spectroscopy showed that surface fresh catalyst contains chromium species state (III) as well higher states (V VI)...

This study demonstrates depleted uranium as a remarkable heterogeneous catalyst for the oxidation of HCl to Cl2. reaction comprises sustainable approach valorise byproduct streams in chemical industry. Bulk α-U3O8 showed an outstanding stability against chlorination, which is crucial its durability catalytic tests. UO2 and γ-UO3 transformed into under conditions. Uranium deposition on different carriers by dry impregnation concluded superiority zirconia support. HAADF-STEM investigations...

Ethylene and propylene are the key building blocks of chemical industry, but current processes unable to close growing gap between demand manufacture. Reported herein is an exceptional europium oxychloride (EuOCl) catalyst for selective (≥95 %) production light olefins from ethane propane by oxychlorination chemistry, thus achieving yields ethylene (90 (40 unparalleled any existing olefin technology. Moreover, EuOCl able process mixtures methane, ethane, produce olefins, thereby reducing...

This work presents the scale-up of room-temperature mechanochemical synthesis nanocorundum (high-surface-area α-Al2O3) from boehmite (γ-AlOOH). transformation on 1 g scale using a laboratory shaker mill had previously been reported. High-energy Simoloyer ball mills equipped with milling chambers sizes ranging to 20 L were used up 50 kg scale, which paves way further increase batch size. Milling made steel and lined silicon nitride (Si3N4) balls steel, zirconia (ZrO2), investigated address...

Heterogeneous catalytic pathways for clean energy conversion involve thousands of elementary steps, but most quantum-mechanical models only a few dozen reactions. We combine extensive density functional theory (DFT) calculations, machine learning (ML) activation barrier prediction, and human intelligence-inspired reaction enumeration identification. This enables automated kinetic modeling CO2 hydrogenation on copper, key process to produce fuels chemicals. construct the largest dataset 152...

Abstract RuO 2 /SnO –Al O 3 has been recently reported as an industrial catalyst for Cl production through HCl oxidation. The stabilizing role of the alumina binder in material, essential its durable performance, is elucidated here. Al prevents chlorination SnO carrier under relevant reaction conditions, whereas, absence, losses exceed 80 wt % very short times owing to volatilization SnCl 4 . Characterization by using X‐ray diffraction, temperature‐programmed reduction with hydrogen, and...