一个多站点的微动力学框架,用于描述干甲改造 (DRM) 在Ni-CeO催化剂中的界面动力学2
Nirenjan Shenoy Padmanabha Naveen1, Kerry M Dooley2, Michael J Janik1
1Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
概括
一个新的微动力学模型揭示了和之间的接口如何影响甲干改造 (DRM) 活动. 纳米粒子的大小决定了甲激活或氧气运输是否限制了反应速度.
科学领域:
- 催化剂是一种催化剂.
- 化学工程是化学工程的重要组成部分.
- 材料科学 材料科学 材料科学
背景情况:
- 氧化物支持的Ni催化剂对于甲干改造 (DRM) 是至关重要的.
- 金属支接口是DRM中O运输和H溢出的关键.
- 了解接口过程对于优化DRM催化剂至关重要.
研究的目的:
- 为Ni-CeO2系统开发一个多站点微动力学模型.
- 阐明接口过程在DRM活动和选择性中的作用.
- 调查Ni纳米粒子大小如何影响反应动力学和失活.
主要方法:
- 为Ni-CeO2.2开发了一种多站点微动力学模型.
- 用密度函数理论 (DFT) 来计算动力参数.
- 进行了全球敏感性分析 (Sobol) 和速率控制程度 (DRC) 分析.
主要成果:
- 模型显示DRM速率对CH4和CO2压力的混合依赖.
- Ni纳米粒子半径 (rm) 是一个主要的几何参数.
- 对于小的Ni纳米粒子来说,CH4激活是速度限制;O-运输限制了较大的.
结论:
- 该模型捕捉到没有明确的焦化途径的过渡到易于失活的模式.
- 这项工作为研究接口介导反应提供了机制框架.
- 该模型作为设计高效DRM催化剂的预测工具.
相关概念视频
Kinetic Energy
43.6K
Kinetic energy is the ability of an object in motion to do work or enact change. It can take on many forms. For instance, water flowing down a waterfall has kinetic energy. In biological systems, particles of light travel and are absorbed by plants to create chemical energy. Animals consume the chemical energy and give off molecules that carry their scent through the air. They also generate kinetic energy when they run away from predators. Entire systems also possess kinetic energy, like the...
43.6K
Enzyme Kinetics
104.4K
Enzymes speed up reactions by lowering the activation energy of the reactants. The speed at which the enzyme turns reactants into products is called the rate of reaction. Several factors impact the rate of reaction, including the number of available reactants. Enzyme kinetics is the study of how an enzyme changes the rate of a reaction.
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
104.4K
Kinetic Molecular Theory: Molecular Velocities, Temperature, and Kinetic Energy
30.0K
The kinetic molecular theory qualitatively explains the behaviors described by the various gas laws. The postulates of this theory may be applied in a more quantitative fashion to derive these individual laws.
30.0K
Interfacial Electrochemical Methods: Overview
911
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current...
911
Dry Friction
997
Dry friction occurs between two solid surfaces in contact as they attempt to move relative to one another. In daily life, dry friction is encountered in various forms, such as when walking on the ground, sliding an object across a table, or rubbing hands together. Despite its ubiquity, the underlying mechanisms behind dry friction are not readily visible.
To illustrate this concept, imagine a wooden crate resting on a rough, non-uniform horizontal surface. When an external force is applied to...
To illustrate this concept, imagine a wooden crate resting on a rough, non-uniform horizontal surface. When an external force is applied to...
997
Drying Shrinkage
389
When hardened concrete is exposed to air with a relative humidity of less than 100 percent, it begins to lose the free water within its capillaries. As this water evaporates, the water initially adsorbed onto the calcium silicate hydrates migrates towards these now empty spaces and eventually evaporates as well. Over time, as more water leaves, the volume of the concrete decreases, a phenomenon known as drying shrinkage.
A portion of this drying shrinkage can be reversed; if the concrete is...
A portion of this drying shrinkage can be reversed; if the concrete is...
389


