Nature Of Synergistic Effect Research Articles

The nature of synergistic effects in transition metal oxides/in-situ intermediate-hydroxides for enhanced oxygen evolution reaction

Oxygen evolution reaction is highly important for hydrogen production via water splitting but requires ∼0.22 V onset overpotential, resulting in at least 15% extra energy consumption even utilized with the benchmark hetero-doped transition-metal hydroxide catalysts. The lack of fundamental understanding on catalyst behaviour and on synergistic mechanisms limit the breakthrough for material design. Here, we systematically summarise a variety of investigations and arguments on the mechanism from the microscale (optimal octahedral intermediate with six M−O coordination) to atomic scale (the active site behaviour). The electron–orbital scale ( e g ) is further described for the intrinsic OER activity. The synergistic effect may also lead to a short-cut pathway of lattice-oxygen-mediated mechanism to achieve a smaller overpotential. This review provides a theoretical reference for the design of advanced catalysts.

Evaluating synergistic effect of optimally controlling commercial building thermal mass portfolios

In order to achieve a sustainable energy future, advanced control paradigms will be critical at both building and grid levels to achieve harmonious integration of energy resources. This research explores the potential for synergistic effects that may exist through communal coordination of commercial building operations. A framework is presented for diurnal planning of multi-building thermal mass and HVAC system operational strategies in consideration of real-time energy prices, peak demand charges, and ancillary service revenues. Optimizing buildings as a portfolio achieved up to seven additional percentage points of cost savings over individually optimized cases, depending on the simulation case study. The magnitude and nature of synergistic effect was ultimately dependent upon the portfolio construction, grid market design, and the conditions faced by buildings when optimized individually. Enhanced energy and cost savings opportunities were observed by taking the novel perspective of optimizing building portfolios in multiple grid markets, motivating the pursuit of future smart grid advancements that take a holistic and communal vantage point.

Insights into the Nature of Synergistic Effects in Proton-Conducting 4,4−1H,1H-Bitriazole-Poly(ethylene oxide) Composites

A nitrogen-containing heterocycle (NCH), 4,4-1H-1H-bi-1,2,3-triazole (bitriazole), capable of mimicking the hydrogen bonding of water in the solid state is synthesized and its ability to conduct protons in the presence of poly(ethylene oxides) under anhydrous conditions is investigated. Bitriazole is shown to have sufficient thermal and electrochemical stability for fuel cell applications. The composites formed between bitriazole and poly(ethylene oxides) give proton conductivities that can be described by the Vogel−Tamman−Fulcher (VTF) equation. These characteristics suggest coupling between polymer segmental motion and ion transport. The bitriazole N-H proton is shown to be the source of conductivity, and bitriazole and poly(ethylene oxides) function synergistically through specific intermolecular interactions and polymer-induced segmental motion to create a pathway for proton transport via structural diffusion.

Single-phase gold/palladium catalyst: The nature of synergistic effect

The liquid phase oxidation of glycerol with oxygen has been studied using mono and bimetallic catalysts based on Au and Pd metals supported on activated carbon, in order to study the effect of the metal on the distribution of the products and on activity of catalysts. It was found that by using bimetallic catalysts (Au–Pd) a strong synergistic effect was shown. By using a preformed nucleating centre we were able to obtain a single alloyed phase, which allowed us to address the synergistic effect to the presence of alloyed Au/Pd. The advantage of using this latter catalyst lies not only in the high activity but also in a prolonged catalyst life. Although a partial leaching of palladium and assembling of the particles have been revealed by ICP and HRTEM respectively, activity after 10 re-cycles decreased less than expected (about 10%).

ChemInform Abstract: The Role of Rate Determining Steps in the Decorporation of Toxic Metal Ions

AbstractReview: (117 refs.

The role of rate determining steps in the decorporation of toxic metal ions

An examination of a variety of experimental data shows that several types of rate determining steps can drastically limit the ability of a chelating agent to react with a toxic metal ion in vivo. Such limitations are important for many metal–chelate formation reactions with very favorable overall thermodynamic changes. Two of the most important of these are the slow ligand exchange reactions and slow rates of movement of ionic chelating agents across cellular membranes to achieve contact with intracellular deposits of toxic metal ions. They have drastic effects on the overall stoichiometry of the decorporation process. A simple model is developed which allow rates of mobilization to be estimated. This model is also applied to the problem of overly rapid metal mobilization which frequently leads to adverse effects. The nature of synergistic effects in chelate therapy is also examined and it is seen that many of these can be explained on the basis of the catalysis of ligand exchange processes or on the basis of the different in vivo distribution of lipophilic and hydrophilic chelating agents.