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Highly dispersed chromium oxide catalysts supported on mesoporous silica (Cr-MSU-x) were prepared via a (N0M n+)I0 pathway with the goal of achieving the high performance oxidative dehydrogenation of propane (ODHP) reaction. The resulting materials exhibited a mesopore structure resembling 3D wormhole-like holes, as characterized by N2 adsorption–desorption isotherms and HR-TEM. Catalytic experimental results revealed that the catalyst with a 0.028 Cr/Si molar ratio showed the highest catalytic activity among the catalysts studied. Two types of chromium species, isolated Cr(VI) and polymeric Cr(VI) species, were observed, as evidenced by H2-temperature-programmed reduction. They were designated as “hard Cr(VI)” and “soft Cr(VI)” sites, respectively. The initial composition of the soft Cr(VI) in the total Cr(VI) is a major determinant factor in the ODHP performance.

This study evaluated the effect of different cooking methods including blanching, boiling, microwaving and steaming on the content of vitamins in vegetables. True retention was estimated using the yield expressed as a ratio of the weight of the cooked sample to the weight of the raw sample. The retention of vitamin C ranged from 0.0 to 91.1% for all cooked samples. Generally, higher retention of vitamin C was observed after microwaving with the lowest retention recorded after boiling. Cooked vegetables were occasionally higher contents of fat-soluble vitamins, including α-tocopherol and β-carotene, than that of their fresh counterparts, but it depends on the type of vegetables. Microwave cooking caused the greatest loss of vitamin K in crown daisy and mallow; in contrast, it caused the least loss of vitamin K in spinach and chard. Cooking may cause changes to the contents of vitamins, but it depends on vegetables and cooking processes.