Long term stable Co-based catalysts for Sabatier reaction under changing feed loads

来自可再生能源的能量可以以氢的形式储存。然而，储存氢气有许多缺点，可以通过所谓的萨巴蒂尔反应将其转化为甲烷。在固定条件下，这种催化反应已经被很好地理解，并经常应用于管束反应器中。然而，由于可再生能源经常波动，氢气供应也是如此，因此Sabatier反应的进料负荷也是如此。这导致在由于热管理能力不足而导致体积流量减少的情况下出现温度热点，特别是在工业应用的25 mm反应堆管中。这可能会导致催化剂的热失活，这是由于催化剂组分的烧结和反应以及表面积损失。本项目的目标是设计一种钴基催化剂，能够在长时间运行的情况下，在变化的负载下保持高活性。一个目的是确定催化剂在原子和纳米尺度上的掺杂对动态进料负荷期间催化层的时间和空间变化的影响。为了合成具有高活性、高选择性和高稳定性的钴基催化剂库，将采用火焰喷雾热解技术。为此，将实现和研究一种不对称的双火焰构型。这项技术将允许使用单一的高温合成过程进行各种独立的催化剂掺杂和催化剂/载体设计。另一个目标是确定在波动的进料负荷下管式反应器内的时间和空间变化。为此，将开发和使用可局部测量饲料和产品流以及高达350°C的壁温的OPERANDO MRI方法。

Energy from renewable sources can be stored in the form of hydrogen. However, stockpiling hydrogen has many disadvantages that can be circumvented transforming it into methane using the so called Sabatier reaction. At stationary conditions this catalytic reaction is already well understood and frequently applied in bundled tubular reactors. However, since the renewable energy sources are often fluctuating and so is the hydrogen supply and therefore the feed loads for the Sabatier reaction. This leads to temperature hot spots in cases of decreasing volume flows due to insufficient heat management capabilities especially in industrially applied 25 mm reactor tubes. This can result in a thermal deactivation of the catalysts due to sintering and reaction of catalytic components and surface area loss. The goal of the present project is the design of cobalt-based catalysts that can sustain high activity under changing loads over long running times. One aim is to determine the influence of catalyst doping at the atom and nanometer scale with respect to time and spatial changes in the catalyst layer during dynamic feed loads. In order to synthesise such Co-based catalyst libraries with high activity, selectivity and stability, the flame spray pyrolysis technique will be employed. To this aim an asymmetrical double flame configuration will be realized and investigated. This technique will allow a large variety of independent catalyst doping’s and catalyst / support designs using a single high temperature synthesis process. Another aim is to determine the time and spatial changes within a tubular reactor under fluctuating feed loads. To this aim operando MRI methods will be developed and employed that can locally measure feed and product streams and temperatures up to wall temperatures of 350 °C.