We present a novel nuclear magnetic resonance (NMR) probe design focused on optimizing the temperature gradient across the sample for high temperature magic angle spinning (MAS) experiments using standard rotors. Computational flow dynamics (CFD) simulations were used to assess and optimize the temperature gradient across the sample under MAS conditions. The chemical shift and linewidth of ²⁰⁷Pb direct polarization in lead nitrate were used to calibrate the sample temperature and temperature gradient, respectively. A temperature gradient of less than 3 °C across the sample was obtained by heating bearing gas flows and adjusting its temperature and flow rate during variable temperature (VT) experiments. A maximum temperature of 350 °C was achieved in this probe using a Varian 5 mm MAS rotor with standard Vespel drive tips and end caps. Time-resolved ¹³C and ¹H MAS NMR experiments were performed at 325 °C and 60 bar to monitor an in-situ mixed phase reverse water gas shift reaction, industrial synthesis of CH₃OH from a mixture of CO₂ and H₂ with a Cu/ZnO/Al₂O₃ catalyst, demonstrating the first in-situ NMR monitoring of a chemical system at temperatures higher than 250 °C in a pressurized environment. The combination of this high-temperature probe and high-pressure rotors will allow for in-situ NMR studies of a great variety of chemical reactions that are inaccessible to conventional NMR setup.

我们提出了一种新颖的核磁共振（NMR）探针设计，旨在优化使用标准转子进行高温魔角旋转（MAS）实验的整个样品的温度梯度。计算流动动力学（CFD）模拟用于评估和优化MAS条件下整个样品的温度梯度。²⁰⁷的化学位移和线宽硝酸铅中的Pb直接极化分别用于校准样品温度和温度梯度。通过加热轴承气流并在可变温度（VT）实验期间调节其温度和流速，获得了整个样品的小于3°C的温度梯度。使用带有标准Vespel驱动尖端和端盖的Varian 5 mm MAS转子，此探头可达到350°C的最高温度。时间分辨¹³ C和^1个H ^ MAS NMR实验在325℃和60巴进行监测原位混合相反向水煤气变换反应，CH的工业合成₃从CO的混合物OH ₂和H ₂与Cu / ZnO / Al ₂ O ₃催化剂，证明了在加压环境中温度高于250°C时化学系统的首次原位NMR监测。这种高温探针和高压转子的组合将允许对传统NMR设置无法进行的多种化学反应进行原位NMR研究。