I don't think so. You can have hotkeys based on different contexts, but not desktops…I'm not sure this is something you'd want since things would get pretty damned complicated with managing hotkeys. You'd need to filter not only on context(particle network, modeller etc.), but on a potentially infinite number of completely user-configurable desktops. So how would you tell on a given desktop, which may contain a POP and a Model viewport, which priority would be given to my ALT-“foo” shortcut that has been defined for both of those contexts in addition to a desktop? Yikes!
If you run a default houdini, the desktops are aliased to the F1,F2,…,F8 keys. Bring up a the Aliases and Variables… window from under the main Settings menu. Note how AF1.AF2,…AF8 (Alt+F key) and the F1,F2,…,F8 keys are binded to switching to the various desktops.