Universal Journal of Catalysis Science

Catalytic Performance of Pd/Al2O3 Catalyst in the Presence of HHDMA Ligand in Acetylene Selective Hydrogenation Process

Maryam Takht Ravanchi, Maryam Rahimi Fard, Hadi Moosavi, Saeed Sahebdelfar — Tue, 28 Nov 2023 00:00:00 +0800

A series of Pd-HHDMA/Al2O3 catalysts were prepared with various Pd and hexadecyl-2-hydroxyethyldimethylammonium dihydrogen phosphate (HHDMA) amounts by the reduction-deposition method. The catalysts were characterized by N2-physisorption, FE-SEM, CO-TPD, TG and FT-IR techniques. Performance tests for tail-end semi-hydrogenation of acetylene to ethylene were performed in a fixed-bed reactor at 60 °C, 10 bar and GHSV=4000 h-1 . All catalysts exhibited egg-shell Pd distribution which is beneficial for selective semihydrogenation reaction. The BET surface area and pore volume of the catalysts decreased with increasing HHDMA content for a given Pd loading. The conversion of acetylene increased with Pd loading and decreased with HHDMA content. The ethylene production increased with HHDMA whereas that of undesirable C4+ oligomerization products (“green oil”), which are coke precursors, was effectively suppressed.

Study of Gas-phase Reactions within the Modified Marcus Model. V. Arrhenius Equation for the Reaction CH3OH + CH3 → CH2OH + CH4

Igor Romanskii — Thu, 19 Oct 2023 00:00:00 +0800

A theoretical study of the kinetics of the gas-phase reaction СН₃OH + СН₃ → СН₂OH + СН₄ (energy calculation level UCCSD (T)/6-311G**//B3LYP/6-31+G**) in the temperature range 2000–10 K was performed. A discussion is carried out within the framework of a modified version of the Marcus model. The obtained results are used to analyze the Arrhenius equation in terms of the change in temperature of each of the parameters included in the expression for the reaction rate constant. In accordance with the change in the influence of various factors on the shape (slope and curvature) of the Arrhenius plot, the temperature intervals 2000 - 600, 600 - 80 and 80 - 10 K are distinguished.

Practicable Artificial Photosynthesis: Its Relevance, Fundamental Challenges and Opportunities

Ibram Ganesh — Tue, 19 Dec 2023 00:00:00 +0800

The single main resource for the survival of humankind on this planet is the sunlight and it is freely coming to every home like the life-supporting gas, oxygen, is coming to every individual. When society becomes master in harvesting such a precious, Omnipresent, carbon-neutral, clean, freely and abundantly available renewable energy resource sunlight in a suitable form of chemical energy such as, H₂, O₂, CO, methanol, gasoline (petrol), diesel, etc., with a minimum conversion efficiency of 10% by using carbon dioxide (CO₂) and water (H₂O) as energy storing materials, which is referred to as the “Practicable Artificial Photosynthesis (PAP)” process, it can be employed for commercial practice with economic viability to meet all the energy needs of the society without any back-up by electricity generated at thermal power plants by burning greenhouse gas CO₂ releasing fossil fuels. In fact, the PAP process is the only option available today for humankind to make energy, environment, economy, and life sustainable on our only habitable planet, Earth. In this article, (i) how the PAP process can change the global energy economy and energy dynamics of the world while solving all the humanities top 10 problems for the next 50 years, (ii) how the entire CO₂ gas generated as a waste across the globe at all the major outlets can be eventually converted into petrol (i.e., gasoline) given the fossil fuels cannot sustain our civilization’s economic growth, (iii) the effectiveness of existing CO₂ sequestration vs. carbon capture and utilization (CCU) processes, (iv) nature’s response to anthropogenic CO₂ gas rise in the atmosphere, (v) steps involved in the realization of a desirable PAP process, (vi) why silicon photovoltaic cell (SPVC) solar panels cannot solve the energy problems of our society considering the outcome of Germany’s Energiewende program, etc., have been meticulously presented and described in this article.

The Importance of Sustainable Biomass Sources in the Development of Porous Carbonaceous Materials-Synthesis and Energy Applications: A Review

Erol Pehlivan, Şerife Parlayıcı — Thu, 12 Oct 2023 00:00:00 +0800

In this review, a variety of planning methods for porous organic materials using different types of biomasses are compiled, and their functions are discussed. Improved pore architectures and variable surfaces were created in porous carbons manufactured from biomass. It is effective and sustainable to use biomass waste, which mostly consists of cellulose, hemicellulose, and lignin. They assemble microtextured structures around one another in multi-channel configurations. The possibility of incorporating porous carbon compounds derived from biomass is being explored due to their distinct surface and structure. These "old type" carbons, which are produced through direct pyrolysis or physical or chemical activation, represent the instantaneous usage of biomass. There has been a lot of research on the chemical activation of biomass to create extremely effective activated porous carbons for gas collection. They consist of a variety of small patterns, pore dispersions, and conductive spines and have adaptive physicochemical properties that permit their application as dynamic stage networks or electroactive materials. The structure of carbon-based materials obtained from biomass has the potential to improve electrochemical energy storage. Energy storage resources are required more frequently every day. Energy storage is essential to meet the energy demands resulting from the interruption of energy sources due to several circumstances. There are many uses for carbon materials, including the storage of energy, the filtration of water and air, and the storage of gases like carbon dioxide (CO₂), nitrogen (N₂), methane (CH₄), and hydrogen (H₂). In this study, the advantages of cellulose-based systems as well as the latest developments and methods for creating high-capacity electronics are highlighted.

H2 as Clean Energy for Sustainable Future

Sovann Khan , Veasna Soum — Fri, 22 Sep 2023 00:00:00 +0800

H₂ is considered a clean fuel used in Fuel cell technology for electricity generation with zero greenhouse gas (GHG) emission. The demand for H₂ gas, typically for fuel cell electric vehicles (FCEVs), is increasing. However, the current H2 production relies on natural gas and coals related to carbon oxide gas emission, which gives back to global warming concerns. Low-carbon production processes are needed to contribute to the United Nation's sustainable development goals (SDGs). Water-splitting reaction using photocatalysis or electrocatalysis is a promising method for producing H₂ from water, which is the earthabundant resource. These H₂ production methods based on catalytic technologies require highly active catalyst materials with long-term stability. The development of non-conventional materials with consideration of nanostructure, multijunction, and defect engineering is explored to achieve highly active catalyst materials. This mini-review discusses a basic understanding of H₂ production from water-splitting reactions via photocatalysis and electrocatalysis, with outstanding examples of recent works reported. Last part, we provide a short study on the H₂ global market and policy in order to conclude the future direction of H₂ energy.