Toast pecans in 12-inch nonstick skillet over medium-high heat, stirring occasionally, until fragrant, about 3 minutes.
Off heat, stir in 1 tablespoon butter, maple syrup and 1/8 teaspoon salt. Return skillet to medium heat and cook, stirring constantly, until nuts are dry and glossy, about 45 seconds;transfer to plate and set aside.
Wipe out skillet. melt remaining 2 tablespoons butter in skillet over medium heat.
Add shallots, orange zest and cayenne, and cook, stirring occasionally, until shallots are softened, about 2 minutes
Stir in flour until combined, then add green beans.
Add chicken broth, orange juice and sage. Increase heat to medium-high, cover and cook until beans are crisp-tender, about 4 minutes
Uncover and cook, stirring occasionally, until beans are tender and sauce has thickened slightly, about 4 minutes. Off heat, season with salt and pepper to taste. Transfer to serving dish, sprinkle with pecans and serve.