Platinum-Group Metals, Alloys and Compounds in Catalysis

A review on coke management during dry reforming of methane

“…The support formed reconstructed layered hydroxide composites following the treatment as established from X-ray diffraction studies [81][82][83]. Previously, some research groups [84][85][86][87][88][89] have also indicated strong metal-metal interaction for supported Ru-Ni and low Ni loading (<2 wt.%) to enhance the reforming activity and limit coking than in the case of either Pd-Ni or Pt-Ni systems under similar conditions. The 0.1 wt.% Ru/0.5 wt.% Ni material showed the best performance of 94-98% conversion for both methane and carbon dioxide with less than 5 wt.% of deposited coke, as similarly found with the 0.1 wt.% Ru/0.5 wt.% Cu system.…”

“…Catalysts containing iron, chromium, and cobalt showed the worst coke deposition of 30 wt.%, very close to that of monometallic counterparts. Previously, some research groups [84][85][86][87][88][89] have also indicated strong metal-metal interaction for supported Ru-Ni and low Ni loading (<2 wt.%) to enhance the reforming activity and limit coking than in the case of either Recently, Pawalec et al [96] demonstrated that varying the Ni amount can influence the reforming properties of Pt-Ni/ZSM-5 catalysts. The materials 0.5 wt.% Pt and 1-12 wt.% Ni loadings were prepared by aqueously assisted sequential impregnation and evaluated at 500-600°C.…”

“…The regeneration process allows coke and other carbonaceous materials deposited on the catalyst surface and within the pores to be adequately cleaned without destroying the structural and compositional integrity of the catalyst. Bimetallic and/or structured catalysts systems are good candidates that ensure low coke deposition and are more thermally stable [71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]. Regeneration is commonly achieved by oxidation of the spent catalyst at temperatures closer to 600°C [71][72][73][74][75].…”

“…Polymeric carbonaceous deposits may require higher temperature and longer treatment time, particularly because of large quantity of energy required to degrade the polymeric chains and favor combustion process [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96]. Bimetallic and/or structured catalysts systems are good candidates that ensure low coke deposition and are more thermally stable [71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]. Therefore, regeneration of these catalysts would be more favorable than for the common catalysts.…”

Microwave Enthrakometric Labs-On-A-Chip and On-Chip Enthrakometric Catalymetry: From Non-Conventional Chemotronics Towards Microwave-Assisted Chemosensors

“…Considering the high catalytic capacity of platinum described above, it is expedient to conduct studies taking into account the surface of the enthrakometer and its catalytic properties. Considering the growing interest in the catalysis on platinum surfaces, including the most exotic forms [29][30][31][32][33][34][35] and excluding the well-known examples [36,37], it becomes possible to use platinum enthrakometers to study the formation of intermetallides, the electrochemical synthesis of organometallic compounds, adducts, etc. Considering the emergence of self-oscillations in a number of reactions in the gaseous phase on the platinum surface [38][39][40][41][42][43], the use of platinum enthrakometers under gas flow in a multiphase catalytic cell allows one to speak about an "autowave" or "self-oscillating" catalymetry on the surface of an enthrakometer under microwave irradiation.…”