Hydrotreating Performance of FCC Diesel and Dibenzothiophene over NiMo Supported Zirconium Modified Al-TUD-1 Catalysts

Hydrodesulfurization of Dibenzothiophene: A Machine Learning Approach

The hydrodesulfurization (HDS) process is widely used in the industry to eliminate sulfur compounds from fuels. However, removing dibenzothiophene (DBT) and its derivatives is a challenge. Here, the key aspects that affect the efficiency of catalysts in the HDS of DBT were investigated using machine learning (ML) algorithms. The conversion of DBT and selectivity was estimated by applying Lasso, Ridge, and Random Forest regression techniques. For the estimation of conversion of DBT, Random Forest and Lasso offer adequate predictions. At the same time, regularized regressions have similar outcomes, which are suitable for selectivity estimations. According to the regression coefficient, the structural parameters are essential predictors for selectivity, highlighting the pore size, and slab length. These properties can connect with aspects like the availability of active sites. The insights gained through ML techniques about the HDS catalysts agree with the interpretations of previous experimental reports.

A current overview of the oxidative desulfurization of fuels utilizing heat and solar light: from materials design to catalysis for clean energy

The ceaseless increase of pollution cases due to the tremendous consumption of fossil fuels has steered the world towards an environmental crisis and necessitated urgency to curtail noxious sulfur oxide emissions. Since the world is moving toward green chemistry, a fuel desulfurization process driven by clean technology is of paramount significance in the field of environmental remediation. Among the novel desulfurization techniques, the oxidative desulfurization (ODS) process has been intensively studied and is highlighted as the rising star to effectuate sulfur-free fuels due to its mild reaction conditions and remarkable desulfurization performances in the past decade. This critical review emphasizes the latest advances in thermal catalytic ODS and photocatalytic ODS related to the design and synthesis routes of myriad materials. This encompasses the engineering of metal oxides, ionic liquids, deep eutectic solvents, polyoxometalates, metal-organic frameworks, metal-free materials and their hybrids in the customization of advantageous properties in terms of morphology, topography, composition and electronic states. The essential connection between catalyst characteristics and performances in ODS will be critically discussed along with corresponding reaction mechanisms to provide thorough insight for shaping future research directions. The impacts of oxidant type, solvent type, temperature and other pivotal factors on the effectiveness of ODS are outlined. Finally, a summary of confronted challenges and future outlooks in the journey to ODS application is presented.

Promoting effects of SO42− on a NiMo/γ-Al2O3 hydrodesulfurization catalyst

SO₄²⁻ anchors to a NiMo/γ-Al₂O₃ catalyst, weakening the metal–support interactions, inhibiting MoS₂ aggregation, increasing the number of Ni–Mo–S sites, and thus improving its activity and stability.

Vanadium Phosphorus Oxide/Siliceous Mesostructured Cellular Foams: efficient and selective for sustainable acrylic acid production via condensation route

A new type of supported vanadium phosphorus oxide (VPO) with self-phase regulation was simply fabricated (organic solvent free) for the first time by depositing the specific VPO precursor NH4(VO2)HPO4 onto the Siliceous Mesostructured Cellular Foams (MCF) with controlled activation. The resulting materials were found to be highly efficient and selective for sustainable acrylic acid (AA) plus methyl acrylate (MA) production via a condensation route between acetic acid (HAc) and formaldehyde (HCHO). A (AA + MA) yield of 83.7% (HCHO input-based) or a (AA + MA) selectivity of 81.7% (converted HAc-based) are achievable at 360 °C. The systematic characterizations and evaluations demonstrate a unique surface regulation occurring between the MCF and the NH4(VO2)HPO4 precursor. NH3 release upon activation of NH4(VO2)HPO4 precursor together with adsorption of NH3 by MCF automatically induces partial reduction of V5+ whose content is fine-tunable by the VPO loading. Such a functionalization simultaneously modifies phase constitution and surface acidity/basicity of catalyst, hence readily controls catalytic performance.

Sacrificial carbonaceous coating over alumina supported Ni–MoS2 catalyst for hydrodesulfurization

Recent results have evidenced that carbon plays an important role in stabilizing the structure of the active phase in catalysts. In this work, carbon-coated alumina was prepared by applying polydopamine (PDA) as a sacrificial carbon source to modify the surface properties of γ-alumina, which then was used as a support to prepare supported NiMo catalysts for hydrodesulfurization (HDS) of dibenzothiophene (DBT). NiMo/Al₂O₃ catalysts exhibited limited hydrodesulfurization performances due to their strong metal-support interaction. Herein, we report an unexpected phenomenon that sacrificial carbon layers can be constructed on the surface of the Al₂O₃ support from the carbonization of polydopamine (PDA) and mediated the interaction between the active site and support. Through the removal of carbon layers and sulfidation, the resulting NiMo catalysts exhibit excellent performance for HDS reaction of dibenzothiophene (DBT), which is associated with adequate loading of residual carbon species, leading to an enhanced amount of active species under sulfidation conditions. Moreover, the facile synthetic strategy can be extended to the stabilization of the active phase on a broad range of supports, providing a general approach for improving the metal-support interaction supported nanocatalysts.

Sacrificial carbon coating over NiMo/Al₂O₃ catalyst effectively tailor the interaction between the active phase and support, which result in more easily reducible active components and enhanced HDS performance.