Ultrasmall Ru nanoparticles supported on chitin nanofibers for hydrogen production from NaBH4 hydrolysis

In this work,a series of chitin-supported Ru catalysts,composed of ultrasmall Ru nanoparticles supported on the chitin nanofibers,with different Ru content from 0.07 wt%to 0.93 wt%,are fabricated.Results from catalyzed NaBH4 hydrolysis experiments indicate that the catalytic activity of the fabricated chitin-supported Ru catalysts increases gradually with the decreasing of Ru content.The rate of hydrogen generation from NaBH4 hydrolysis catalyzed by the catalyst with 0.07 wt%Ru content is as high as 55.29 L min 1 gRu-1 at 30℃,and this reaction exhibits activation energy of 39.16 kJ/mol.The augment of NaBH4 dosage in the experiments does not weaken the catalytic activity.In addition,the fabricated chitin-supported Ru catalysts show excellent durability in NaBH4 hydrolysis,with only 9.2%activity loss after used for 20 cycles.With excellent catalytic activity and durability,the as-obtained Ru catalysts provide a promising choice for promoting hydrogen production from NaBH4 hydrolysis.

Search for QCD critical point by transverse velocity dependence of anti-deuteron to deuteron ratio

We propose the transverse velocity(β_T) dependence of the anti-deuteron to deuteron ratio as a new observable to search for the QCD critical point in heavy-ion collisions.The QCD critical point can attract the system evolution trajectory in the QCD phase diagram,which is known as the focusing effect.To quantify this effect,we employ the thermal and hadronic transport model to simulate the dynamical particle emission along a hypothetical focusing trajectory near the critical point.We found that the focusing effect can lead to anomalous β_T dependence on ■/p,■/d and ■/~3 He ratios.We examined the β_T dependence of ■/p and ■/d ratios of central Au+Au collisions at ■=7.7 to 200 GeV measured by the STAR experiment at RHIC.Surprisingly,we only observe a negative slope in β_T dependence of ■/d ratio at ■=19.6 GeV,which indicates the trajectory evolution has passed through the critical region.In the future,we could constrain the location of the critical point and/or width of the critical region by conducting precise measurements on the β_T dependence of the ■/d ratio at different energies and rapidity.