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Thermal stability of carbon based materials is crucial to their catalytic performance in oxidative dehydrogenation at high temperature. This work aims at exploring the mechanism for B doping to improve thermal stability and catalytic performance of N, B co-doped carbon (HC-N-B) for oxidative dehydrogenation of propane using CO2, which was prepared by using humic acids (HAs) extracted from Sheng Li lignite. Porous carbon (HC) from humic acids has low thermal stability in CO2 and N-doping resulted in the decreased thermal stability of HC. Interestingly, B doping HC-N showed very high thermal stability in CO2 (almost no weight-loss). Thus, HC-N-B could be used as considerable stable carbon catalysts with high catalytic activity for oxidative dehydrogenation of propane using CO2. Compared to porous carbon (HC) and N-doping porous carbon (HC-N) from HAs, the HC-N-B could remain the high catalytic dehydrogenation activity in 5 h. It was found that B doping on the defect structure in carbon skeleton structure of the HC-N could greatly increase the thermal stability of surface defects of N-doped porous carbon in CO2, and molecular simulation calculation results further confirmed that the existence of C-N-B and BC3 structure in the carbon skeleton defects could act as catalytic active sites in dehydrogenation reaction, which could slightly enhance the catalytic activity of the HC-N-B and largely improved its catalytic stability of the HC-N-B. [ABSTRACT FROM AUTHOR]

In this paper, we propose coding-aided K-means clustering (CKMC) blind transceiver for space shift keying (SSK) multiple-input multiple-output (MIMO) systems, where the training of channel state information (CSI) is not required for detection. For the scenario where transmitter is with limited processing capability and limited power such as Internet Of Things (IOT) and wireless sensor network (WSN), SSK is preferable to typical MIMO due to its simplicity and improved energy efficiency. The proposed CKMC blind communication trades off receiver complexity for training overhead, which provides better spectral efficiency compared to training-based transceiver. In CKMC, the blind communication problem is converted to the problems of clustering and permutation; for the clustering problem, we propose K-means clustering (KMC) detector to reduce detection complexity; for the permutation problem, we propose to perform depermutation with the aid of channel decoding. The analysis of CKMC blind transceiver is conducted, and the verification of performance of CKMC is presented in the simulations section. The results show that the performance of CKMC blind communication can closely approach the performance of optimal receiver with perfect CSI under certain scenarios. [ABSTRACT FROM PUBLISHER]