Useful for emote servers you're in but whose emotes you cannot access. Will open the greyed out emoji in a new tab.

discord.nitroemojinewtab.user.js

// ==UserScript==
// @name        Discord Nitro Emoji In New Tab
// @description Useful for emote servers you're in but whose emotes you cannot access if you don't have Nitro. Will open the greyed out emoji in a new tab.
// @namespace   Violentmonkey Scripts
// @grant       GM_addStyle
// @require     http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js
// @require     https://raw.githubusercontent.com/pie6k/jquery.initialize/master/jquery.initialize.min.js
// @match       *://discordapp.com/*
//
// ==/UserScript==

$(document).on("click", "div[class*='emojiItem-']", function(e) {
    e.preventDefault();
    if ($(this).attr("class").indexOf("disabled") != -1) {
        var url = $(this).attr("style").split("\"")[1].split("\"")[0];
        console.log(url);
        window.open(url, '_blank');
    }
});